SqlHelper

用来用去，还是这个好用

// ===============================================================================
// Microsoft Data Access Application Block for .NET
// http://msdn.microsoft.com/library/en-us/dnbda/html/daab-rm.asp
//
// SQLHelper.cs
//
// This file contains the implementations of the SqlHelper and SqlHelperParameterCache
// classes.
//
// For more information see the Data Access Application Block Implementation Overview. 
// ===============================================================================
// Release history
// VERSION    DESCRIPTION
//   2.0    Added support for FillDataset, UpdateDataset and "Param" helper methods
//
// ===============================================================================
// Copyright (C) 2000-2001 Microsoft Corporation
// All rights reserved.
// THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY
// OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT
// LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR
// FITNESS FOR A PARTICULAR PURPOSE.
// ==============================================================================

using System;
using System.Data;
using System.Xml;
using System.Data.SqlClient;
using System.Collections;

namespace F.Studio.Data.Util
{
    /// <summary>
    /// The SqlHelper class is intended to encapsulate high performance, scalable best practices for 
    /// common uses of SqlClient
    /// </summary>
    public sealed class SqlHelper
    {
        #region private utility methods & constructors

        // Since this class provides only static methods, make the default constructor private to prevent 
        // instances from being created with "new SqlHelper()"
        private SqlHelper() {}

        /// <summary>
        /// This method is used to attach array of SqlParameters to a SqlCommand.
        /// 
        /// This method will assign a value of DbNull to any parameter with a direction of
        /// InputOutput and a value of null.  
        /// 
        /// This behavior will prevent default values from being used, but
        /// this will be the less common case than an intended pure output parameter (derived as InputOutput)
        /// where the user provided no input value.
        /// </summary>
        /// <param name="command">The command to which the parameters will be added</param>
        /// <param name="commandParameters">An array of SqlParameters to be added to command</param>
        private static void AttachParameters(SqlCommand command, SqlParameter[] commandParameters)
        {
            if( command == null ) throw new ArgumentNullException( "command" );
            if( commandParameters != null )
            {
                foreach (SqlParameter p in commandParameters)
                {
                    if( p != null )
                    {
                        // Check for derived output value with no value assigned
                        if ( ( p.Direction == ParameterDirection.InputOutput || 
                            p.Direction == ParameterDirection.Input ) && 
                            (p.Value == null))
                        {
                            p.Value = DBNull.Value;
                        }
                        command.Parameters.Add(p);
                    }
                }
            }
        }

        /// <summary>
        /// This method assigns dataRow column values to an array of SqlParameters
        /// </summary>
        /// <param name="commandParameters">Array of SqlParameters to be assigned values</param>
        /// <param name="dataRow">The dataRow used to hold the stored procedure's parameter values</param>
        private static void AssignParameterValues(SqlParameter[] commandParameters, DataRow dataRow)
        {
            if ((commandParameters == null) || (dataRow == null)) 
            {
                // Do nothing if we get no data
                return;
            }

            int i = 0;
            // Set the parameters values
            foreach(SqlParameter commandParameter in commandParameters)
            {
                // Check the parameter name
                if( commandParameter.ParameterName == null || 
                    commandParameter.ParameterName.Length <= 1 )
                    throw new Exception( 
                        string.Format( 
                            "Please provide a valid parameter name on the parameter #{0}, the ParameterName property has the following value: '{1}'.", 
                            i, commandParameter.ParameterName ) );
                if (dataRow.Table.Columns.IndexOf(commandParameter.ParameterName.Substring(1)) != -1)
                    commandParameter.Value = dataRow[commandParameter.ParameterName.Substring(1)];
                i++;
            }
        }

        /// <summary>
        /// This method assigns an array of values to an array of SqlParameters
        /// </summary>
        /// <param name="commandParameters">Array of SqlParameters to be assigned values</param>
        /// <param name="parameterValues">Array of objects holding the values to be assigned</param>
        private static void AssignParameterValues(SqlParameter[] commandParameters, object[] parameterValues)
        {
            if ((commandParameters == null) || (parameterValues == null)) 
            {
                // Do nothing if we get no data
                return;
            }

            // We must have the same number of values as we pave parameters to put them in
            if (commandParameters.Length != parameterValues.Length)
            {
                throw new ArgumentException("Parameter count does not match Parameter Value count.");
            }

            // Iterate through the SqlParameters, assigning the values from the corresponding position in the 
            // value array
            for (int i = 0, j = commandParameters.Length; i < j; i++)
            {
                // If the current array value derives from IDbDataParameter, then assign its Value property
                if (parameterValues[i] is IDbDataParameter)
                {
                    IDbDataParameter paramInstance = (IDbDataParameter)parameterValues[i];
                    if( paramInstance.Value == null )
                    {
                        commandParameters[i].Value = DBNull.Value; 
                    }
                    else
                    {
                        commandParameters[i].Value = paramInstance.Value;
                    }
                }
                else if (parameterValues[i] == null)
                {
                    commandParameters[i].Value = DBNull.Value;
                }
                else
                {
                    commandParameters[i].Value = parameterValues[i];
                }
            }
        }

        /// <summary>
        /// This method opens (if necessary) and assigns a connection, transaction, command type and parameters 
        /// to the provided command
        /// </summary>
        /// <param name="command">The SqlCommand to be prepared</param>
        /// <param name="connection">A valid SqlConnection, on which to execute this command</param>
        /// <param name="transaction">A valid SqlTransaction, or 'null'</param>
        /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">The stored procedure name or T-SQL command</param>
        /// <param name="commandParameters">An array of SqlParameters to be associated with the command or 'null' if no parameters are required</param>
        /// <param name="mustCloseConnection"><c>true</c> if the connection was opened by the method, otherwose is false.</param>
        private static void PrepareCommand(SqlCommand command, SqlConnection connection, SqlTransaction transaction, CommandType commandType, string commandText, SqlParameter[] commandParameters, out bool mustCloseConnection )
        {
            if( command == null ) throw new ArgumentNullException( "command" );
            if( commandText == null || commandText.Length == 0 ) throw new ArgumentNullException( "commandText" );

            // If the provided connection is not open, we will open it
            if (connection.State != ConnectionState.Open)
            {
                mustCloseConnection = true;
                connection.Open();
            }
            else
            {
                mustCloseConnection = false;
            }

            // Associate the connection with the command
            command.Connection = connection;

            // Set the command text (stored procedure name or SQL statement)
            command.CommandText = commandText;

            // If we were provided a transaction, assign it
            if (transaction != null)
            {
                if( transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );
                command.Transaction = transaction;
            }

            // Set the command type
            command.CommandType = commandType;

            // Attach the command parameters if they are provided
            if (commandParameters != null)
            {
                AttachParameters(command, commandParameters);
            }
            return;
        }

        #endregion private utility methods & constructors

        #region ExecuteNonQuery

        /// <summary>
        /// Execute a SqlCommand (that returns no resultset and takes no parameters) against the database specified in 
        /// the connection string
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///  int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders");
        /// </remarks>
        /// <param name="connectionString">A valid connection string for a SqlConnection</param>
        /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">The stored procedure name or T-SQL command</param>
        /// <returns>An int representing the number of rows affected by the command</returns>
        public static int ExecuteNonQuery(string connectionString, CommandType commandType, string commandText)
        {
            // Pass through the call providing null for the set of SqlParameters
            return ExecuteNonQuery(connectionString, commandType, commandText, (SqlParameter[])null);
        }

        /// <summary>
        /// Execute a SqlCommand (that returns no resultset) against the database specified in the connection string 
        /// using the provided parameters
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///  int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));
        /// </remarks>
        /// <param name="connectionString">A valid connection string for a SqlConnection</param>
        /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">The stored procedure name or T-SQL command</param>
        /// <param name="commandParameters">An array of SqlParamters used to execute the command</param>
        /// <returns>An int representing the number of rows affected by the command</returns>
        public static int ExecuteNonQuery(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );

            // Create & open a SqlConnection, and dispose of it after we are done
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                connection.Open();

                // Call the overload that takes a connection in place of the connection string
                return ExecuteNonQuery(connection, commandType, commandText, commandParameters);
            }
        }

        /// <summary>
        /// Execute a stored procedure via a SqlCommand (that returns no resultset) against the database specified in 
        /// the connection string using the provided parameter values.  This method will query the database to discover the parameters for the 
        /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
        /// </summary>
        /// <remarks>
        /// This method provides no access to output parameters or the stored procedure's return value parameter.
        /// 
        /// e.g.:  
        ///  int result = ExecuteNonQuery(connString, "PublishOrders", 24, 36);
        /// </remarks>
        /// <param name="connectionString">A valid connection string for a SqlConnection</param>
        /// <param name="spName">The name of the stored prcedure</param>
        /// <param name="parameterValues">An array of objects to be assigned as the input values of the stored procedure</param>
        /// <returns>An int representing the number of rows affected by the command</returns>
        public static int ExecuteNonQuery(string connectionString, string spName, params object[] parameterValues)
        {
            if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );
            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            // If we receive parameter values, we need to figure out where they go
            if ((parameterValues != null) && (parameterValues.Length > 0)) 
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                // Assign the provided values to these parameters based on parameter order
                AssignParameterValues(commandParameters, parameterValues);

                // Call the overload that takes an array of SqlParameters
                return ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName, commandParameters);
            }
            else 
            {
                // Otherwise we can just call the SP without params
                return ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName);
            }
        }

        /// <summary>
        /// Execute a SqlCommand (that returns no resultset and takes no parameters) against the provided SqlConnection. 
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///  int result = ExecuteNonQuery(conn, CommandType.StoredProcedure, "PublishOrders");
        /// </remarks>
        /// <param name="connection">A valid SqlConnection</param>
        /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">The stored procedure name or T-SQL command</param>
        /// <returns>An int representing the number of rows affected by the command</returns>
        public static int ExecuteNonQuery(SqlConnection connection, CommandType commandType, string commandText)
        {
            // Pass through the call providing null for the set of SqlParameters
            return ExecuteNonQuery(connection, commandType, commandText, (SqlParameter[])null);
        }

        /// <summary>
        /// Execute a SqlCommand (that returns no resultset) against the specified SqlConnection 
        /// using the provided parameters.
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///  int result = ExecuteNonQuery(conn, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));
        /// </remarks>
        /// <param name="connection">A valid SqlConnection</param>
        /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">The stored procedure name or T-SQL command</param>
        /// <param name="commandParameters">An array of SqlParamters used to execute the command</param>
        /// <returns>An int representing the number of rows affected by the command</returns>
        public static int ExecuteNonQuery(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {    
            if( connection == null ) throw new ArgumentNullException( "connection" );

            // Create a command and prepare it for execution
            SqlCommand cmd = new SqlCommand();
            bool mustCloseConnection = false;
            PrepareCommand(cmd, connection, (SqlTransaction)null, commandType, commandText, commandParameters, out mustCloseConnection );
            
            // Finally, execute the command
            int retval = cmd.ExecuteNonQuery();
            
            // Detach the SqlParameters from the command object, so they can be used again
            cmd.Parameters.Clear();
            if( mustCloseConnection )
                connection.Close();
            return retval;
        }

        /// <summary>
        /// Execute a stored procedure via a SqlCommand (that returns no resultset) against the specified SqlConnection 
        /// using the provided parameter values.  This method will query the database to discover the parameters for the 
        /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
        /// </summary>
        /// <remarks>
        /// This method provides no access to output parameters or the stored procedure's return value parameter.
        /// 
        /// e.g.:  
        ///  int result = ExecuteNonQuery(conn, "PublishOrders", 24, 36);
        /// </remarks>
        /// <param name="connection">A valid SqlConnection</param>
        /// <param name="spName">The name of the stored procedure</param>
        /// <param name="parameterValues">An array of objects to be assigned as the input values of the stored procedure</param>
        /// <returns>An int representing the number of rows affected by the command</returns>
        public static int ExecuteNonQuery(SqlConnection connection, string spName, params object[] parameterValues)
        {
            if( connection == null ) throw new ArgumentNullException( "connection" );
            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            // If we receive parameter values, we need to figure out where they go
            if ((parameterValues != null) && (parameterValues.Length > 0)) 
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                // Assign the provided values to these parameters based on parameter order
                AssignParameterValues(commandParameters, parameterValues);

                // Call the overload that takes an array of SqlParameters
                return ExecuteNonQuery(connection, CommandType.StoredProcedure, spName, commandParameters);
            }
            else 
            {
                // Otherwise we can just call the SP without params
                return ExecuteNonQuery(connection, CommandType.StoredProcedure, spName);
            }
        }

        /// <summary>
        /// Execute a SqlCommand (that returns no resultset and takes no parameters) against the provided SqlTransaction. 
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///  int result = ExecuteNonQuery(trans, CommandType.StoredProcedure, "PublishOrders");
        /// </remarks>
        /// <param name="transaction">A valid SqlTransaction</param>
        /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">The stored procedure name or T-SQL command</param>
        /// <returns>An int representing the number of rows affected by the command</returns>
        public static int ExecuteNonQuery(SqlTransaction transaction, CommandType commandType, string commandText)
        {
            // Pass through the call providing null for the set of SqlParameters
            return ExecuteNonQuery(transaction, commandType, commandText, (SqlParameter[])null);
        }

        /// <summary>
        /// Execute a SqlCommand (that returns no resultset) against the specified SqlTransaction
        /// using the provided parameters.
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///  int result = ExecuteNonQuery(trans, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
        /// </remarks>
        /// <param name="transaction">A valid SqlTransaction</param>
        /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">The stored procedure name or T-SQL command</param>
        /// <param name="commandParameters">An array of SqlParamters used to execute the command</param>
        /// <returns>An int representing the number of rows affected by the command</returns>
        public static int ExecuteNonQuery(SqlTransaction transaction, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            if( transaction == null ) throw new ArgumentNullException( "transaction" );
            if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );

            // Create a command and prepare it for execution
            SqlCommand cmd = new SqlCommand();
            bool mustCloseConnection = false;
            PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection );
                
            // Finally, execute the command
            int retval = cmd.ExecuteNonQuery();
                
            // Detach the SqlParameters from the command object, so they can be used again
            cmd.Parameters.Clear();
            return retval;
        }

        /// <summary>
        /// Execute a stored procedure via a SqlCommand (that returns no resultset) against the specified 
        /// SqlTransaction using the provided parameter values.  This method will query the database to discover the parameters for the 
        /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
        /// </summary>
        /// <remarks>
        /// This method provides no access to output parameters or the stored procedure's return value parameter.
        /// 
        /// e.g.:  
        ///  int result = ExecuteNonQuery(conn, trans, "PublishOrders", 24, 36);
        /// </remarks>
        /// <param name="transaction">A valid SqlTransaction</param>
        /// <param name="spName">The name of the stored procedure</param>
        /// <param name="parameterValues">An array of objects to be assigned as the input values of the stored procedure</param>
        /// <returns>An int representing the number of rows affected by the command</returns>
        public static int ExecuteNonQuery(SqlTransaction transaction, string spName, params object[] parameterValues)
        {
            if( transaction == null ) throw new ArgumentNullException( "transaction" );
            if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );
            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            // If we receive parameter values, we need to figure out where they go
            if ((parameterValues != null) && (parameterValues.Length > 0)) 
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                // Assign the provided values to these parameters based on parameter order
                AssignParameterValues(commandParameters, parameterValues);

                // Call the overload that takes an array of SqlParameters
                return ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName, commandParameters);
            }
            else 
            {
                // Otherwise we can just call the SP without params
                return ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName);
            }
        }

        #endregion ExecuteNonQuery

        #region ExecuteDataset

        /// <summary>
        /// Execute a SqlCommand (that returns a resultset and takes no parameters) against the database specified in 
        /// the connection string. 
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///  DataSet ds = ExecuteDataset(connString, CommandType.StoredProcedure, "GetOrders");
        /// </remarks>
        /// <param name="connectionString">A valid connection string for a SqlConnection</param>
        /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">The stored procedure name or T-SQL command</param>
        /// <returns>A dataset containing the resultset generated by the command</returns>
        public static DataSet ExecuteDataset(string connectionString, CommandType commandType, string commandText)
        {
            // Pass through the call providing null for the set of SqlParameters
            return ExecuteDataset(connectionString, commandType, commandText, (SqlParameter[])null);
        }

        /// <summary>
        /// Execute a SqlCommand (that returns a resultset) against the database specified in the connection string 
        /// using the provided parameters.
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///  DataSet ds = ExecuteDataset(connString, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
        /// </remarks>
        /// <param name="connectionString">A valid connection string for a SqlConnection</param>
        /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">The stored procedure name or T-SQL command</param>
        /// <param name="commandParameters">An array of SqlParamters used to execute the command</param>
        /// <returns>A dataset containing the resultset generated by the command</returns>
        public static DataSet ExecuteDataset(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );

            // Create & open a SqlConnection, and dispose of it after we are done
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                connection.Open();

                // Call the overload that takes a connection in place of the connection string
                return ExecuteDataset(connection, commandType, commandText, commandParameters);
            }
        }

        /// <summary>
        /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the database specified in 
        /// the connection string using the provided parameter values.  This method will query the database to discover the parameters for the 
        /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
        /// </summary>
        /// <remarks>
        /// This method provides no access to output parameters or the stored procedure's return value parameter.
        /// 
        /// e.g.:  
        ///  DataSet ds = ExecuteDataset(connString, "GetOrders", 24, 36);
        /// </remarks>
        /// <param name="connectionString">A valid connection string for a SqlConnection</param>
        /// <param name="spName">The name of the stored procedure</param>
        /// <param name="parameterValues">An array of objects to be assigned as the input values of the stored procedure</param>
        /// <returns>A dataset containing the resultset generated by the command</returns>
        public static DataSet ExecuteDataset(string connectionString, string spName, params object[] parameterValues)
        {
            if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );
            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );
            
            // If we receive parameter values, we need to figure out where they go
            if ((parameterValues != null) && (parameterValues.Length > 0)) 
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                // Assign the provided values to these parameters based on parameter order
                AssignParameterValues(commandParameters, parameterValues);

                // Call the overload that takes an array of SqlParameters
                return ExecuteDataset(connectionString, CommandType.StoredProcedure, spName, commandParameters);
            }
            else 
            {
                // Otherwise we can just call the SP without params
                return ExecuteDataset(connectionString, CommandType.StoredProcedure, spName);
            }
        }

        /// <summary>
        /// Execute a SqlCommand (that returns a resultset and takes no parameters) against the provided SqlConnection. 
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///  DataSet ds = ExecuteDataset(conn, CommandType.StoredProcedure, "GetOrders");
        /// </remarks>
        /// <param name="connection">A valid SqlConnection</param>
        /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">The stored procedure name or T-SQL command</param>
        /// <returns>A dataset containing the resultset generated by the command</returns>
        public static DataSet ExecuteDataset(SqlConnection connection, CommandType commandType, string commandText)
        {
            // Pass through the call providing null for the set of SqlParameters
            return ExecuteDataset(connection, commandType, commandText, (SqlParameter[])null);
        }
        
        /// <summary>
        /// Execute a SqlCommand (that returns a resultset) against the specified SqlConnection 
        /// using the provided parameters.
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///  DataSet ds = ExecuteDataset(conn, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
        /// </remarks>
        /// <param name="connection">A valid SqlConnection</param>
        /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">The stored procedure name or T-SQL command</param>
        /// <param name="commandParameters">An array of SqlParamters used to execute the command</param>
        /// <returns>A dataset containing the resultset generated by the command</returns>
        public static DataSet ExecuteDataset(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            if( connection == null ) throw new ArgumentNullException( "connection" );

            // Create a command and prepare it for execution
            SqlCommand cmd = new SqlCommand();
            bool mustCloseConnection = false;
            PrepareCommand(cmd, connection, (SqlTransaction)null, commandType, commandText, commandParameters, out mustCloseConnection );
                
            // Create the DataAdapter & DataSet
            using( SqlDataAdapter da = new SqlDataAdapter(cmd) )
            {
                DataSet ds = new DataSet();

                // Fill the DataSet using default values for DataTable names, etc
                da.Fill(ds);
                
                // Detach the SqlParameters from the command object, so they can be used again
                cmd.Parameters.Clear();

                if( mustCloseConnection )
                    connection.Close();

                // Return the dataset
                return ds;
            }    
        }
        
        /// <summary>
        /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the specified SqlConnection 
        /// using the provided parameter values.  This method will query the database to discover the parameters for the 
        /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
        /// </summary>
        /// <remarks>
        /// This method provides no access to output parameters or the stored procedure's return value parameter.
        /// 
        /// e.g.:  
        ///  DataSet ds = ExecuteDataset(conn, "GetOrders", 24, 36);
        /// </remarks>
        /// <param name="connection">A valid SqlConnection</param>
        /// <param name="spName">The name of the stored procedure</param>
        /// <param name="parameterValues">An array of objects to be assigned as the input values of the stored procedure</param>
        /// <returns>A dataset containing the resultset generated by the command</returns>
        public static DataSet ExecuteDataset(SqlConnection connection, string spName, params object[] parameterValues)
        {
            if( connection == null ) throw new ArgumentNullException( "connection" );
            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            // If we receive parameter values, we need to figure out where they go
            if ((parameterValues != null) && (parameterValues.Length > 0)) 
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                // Assign the provided values to these parameters based on parameter order
                AssignParameterValues(commandParameters, parameterValues);

                // Call the overload that takes an array of SqlParameters
                return ExecuteDataset(connection, CommandType.StoredProcedure, spName, commandParameters);
            }
            else 
            {
                // Otherwise we can just call the SP without params
                return ExecuteDataset(connection, CommandType.StoredProcedure, spName);
            }
        }

        /// <summary>
        /// Execute a SqlCommand (that returns a resultset and takes no parameters) against the provided SqlTransaction. 
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///  DataSet ds = ExecuteDataset(trans, CommandType.StoredProcedure, "GetOrders");
        /// </remarks>
        /// <param name="transaction">A valid SqlTransaction</param>
        /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">The stored procedure name or T-SQL command</param>
        /// <returns>A dataset containing the resultset generated by the command</returns>
        public static DataSet ExecuteDataset(SqlTransaction transaction, CommandType commandType, string commandText)
        {
            // Pass through the call providing null for the set of SqlParameters
            return ExecuteDataset(transaction, commandType, commandText, (SqlParameter[])null);
        }
        
        /// <summary>
        /// Execute a SqlCommand (that returns a resultset) against the specified SqlTransaction
        /// using the provided parameters.
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///  DataSet ds = ExecuteDataset(trans, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
        /// </remarks>
        /// <param name="transaction">A valid SqlTransaction</param>
        /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">The stored procedure name or T-SQL command</param>
        /// <param name="commandParameters">An array of SqlParamters used to execute the command</param>
        /// <returns>A dataset containing the resultset generated by the command</returns>
        public static DataSet ExecuteDataset(SqlTransaction transaction, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            if( transaction == null ) throw new ArgumentNullException( "transaction" );
            if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );

            // Create a command and prepare it for execution
            SqlCommand cmd = new SqlCommand();
            bool mustCloseConnection = false;
            PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection );
                
            // Create the DataAdapter & DataSet
            using( SqlDataAdapter da = new SqlDataAdapter(cmd) )
            {
                DataSet ds = new DataSet();

                // Fill the DataSet using default values for DataTable names, etc
                da.Fill(ds);
                
                // Detach the SqlParameters from the command object, so they can be used again
                cmd.Parameters.Clear();

                // Return the dataset
                return ds;
            }    
        }
        
        /// <summary>
        /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the specified 
        /// SqlTransaction using the provided parameter values.  This method will query the database to discover the parameters for the 
        /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
        /// </summary>
        /// <remarks>
        /// This method provides no access to output parameters or the stored procedure's return value parameter.
        /// 
        /// e.g.:  
        ///  DataSet ds = ExecuteDataset(trans, "GetOrders", 24, 36);
        /// </remarks>
        /// <param name="transaction">A valid SqlTransaction</param>
        /// <param name="spName">The name of the stored procedure</param>
        /// <param name="parameterValues">An array of objects to be assigned as the input values of the stored procedure</param>
        /// <returns>A dataset containing the resultset generated by the command</returns>
        public static DataSet ExecuteDataset(SqlTransaction transaction, string spName, params object[] parameterValues)
        {
            if( transaction == null ) throw new ArgumentNullException( "transaction" );
            if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );
            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );
            
            // If we receive parameter values, we need to figure out where they go
            if ((parameterValues != null) && (parameterValues.Length > 0)) 
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                // Assign the provided values to these parameters based on parameter order
                AssignParameterValues(commandParameters, parameterValues);

                // Call the overload that takes an array of SqlParameters
                return ExecuteDataset(transaction, CommandType.StoredProcedure, spName, commandParameters);
            }
            else 
            {
                // Otherwise we can just call the SP without params
                return ExecuteDataset(transaction, CommandType.StoredProcedure, spName);
            }
        }

        #endregion ExecuteDataset
        
        #region ExecuteReader

        /// <summary>
        /// This enum is used to indicate whether the connection was provided by the caller, or created by SqlHelper, so that
        /// we can set the appropriate CommandBehavior when calling ExecuteReader()
        /// </summary>
        private enum SqlConnectionOwnership    
        {
            /// <summary>Connection is owned and managed by SqlHelper</summary>
            Internal, 
            /// <summary>Connection is owned and managed by the caller</summary>
            External
        }

        /// <summary>
        /// Create and prepare a SqlCommand, and call ExecuteReader with the appropriate CommandBehavior.
        /// </summary>
        /// <remarks>
        /// If we created and opened the connection, we want the connection to be closed when the DataReader is closed.
        /// 
        /// If the caller provided the connection, we want to leave it to them to manage.
        /// </remarks>
        /// <param name="connection">A valid SqlConnection, on which to execute this command</param>
        /// <param name="transaction">A valid SqlTransaction, or 'null'</param>
        /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">The stored procedure name or T-SQL command</param>
        /// <param name="commandParameters">An array of SqlParameters to be associated with the command or 'null' if no parameters are required</param>
        /// <param name="connectionOwnership">Indicates whether the connection parameter was provided by the caller, or created by SqlHelper</param>
        /// <returns>SqlDataReader containing the results of the command</returns>
        private static SqlDataReader ExecuteReader(SqlConnection connection, SqlTransaction transaction, CommandType commandType, string commandText, SqlParameter[] commandParameters, SqlConnectionOwnership connectionOwnership)
        {    
            if( connection == null ) throw new ArgumentNullException( "connection" );

            bool mustCloseConnection = false;
            // Create a command and prepare it for execution
            SqlCommand cmd = new SqlCommand();
            try
            {
                PrepareCommand(cmd, connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection );
            
                // Create a reader
                SqlDataReader dataReader;

                // Call ExecuteReader with the appropriate CommandBehavior
                if (connectionOwnership == SqlConnectionOwnership.External)
                {
                    dataReader = cmd.ExecuteReader();
                }
                else
                {
                    dataReader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
                }
            
                // Detach the SqlParameters from the command object, so they can be used again.
                // HACK: There is a problem here, the output parameter values are fletched 
                // when the reader is closed, so if the parameters are detached from the command
                // then the SqlReader can磘 set its values. 
                // When this happen, the parameters can磘 be used again in other command.
                bool canClear = true;
                foreach(SqlParameter commandParameter in cmd.Parameters)
                {
                    if (commandParameter.Direction != ParameterDirection.Input)
                        canClear = false;
                }
            
                if (canClear)
                {
                    cmd.Parameters.Clear();
                }

                return dataReader;
            }
            catch
            {
                if( mustCloseConnection )
                    connection.Close();
                throw;
            }
        }

        /// <summary>
        /// Execute a SqlCommand (that returns a resultset and takes no parameters) against the database specified in 
        /// the connection string. 
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///  SqlDataReader dr = ExecuteReader(connString, CommandType.StoredProcedure, "GetOrders");
        /// </remarks>
        /// <param name="connectionString">A valid connection string for a SqlConnection</param>
        /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">The stored procedure name or T-SQL command</param>
        /// <returns>A SqlDataReader containing the resultset generated by the command</returns>
        public static SqlDataReader ExecuteReader(string connectionString, CommandType commandType, string commandText)
        {
            // Pass through the call providing null for the set of SqlParameters
            return ExecuteReader(connectionString, commandType, commandText, (SqlParameter[])null);
        }

        /// <summary>
        /// Execute a SqlCommand (that returns a resultset) against the database specified in the connection string 
        /// using the provided parameters.
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///  SqlDataReader dr = ExecuteReader(connString, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
        /// </remarks>
        /// <param name="connectionString">A valid connection string for a SqlConnection</param>
        /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">The stored procedure name or T-SQL command</param>
        /// <param name="commandParameters">An array of SqlParamters used to execute the command</param>
        /// <returns>A SqlDataReader containing the resultset generated by the command</returns>
        public static SqlDataReader ExecuteReader(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );
            SqlConnection connection = null;
            try
            {
                connection = new SqlConnection(connectionString);
                connection.Open();

                // Call the private overload that takes an internally owned connection in place of the connection string
                return ExecuteReader(connection, null, commandType, commandText, commandParameters,SqlConnectionOwnership.Internal);
            }
            catch
            {
                // If we fail to return the SqlDatReader, we need to close the connection ourselves
                if( connection != null ) connection.Close();
                throw;
            }
            
        }

        /// <summary>
        /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the database specified in 
        /// the connection string using the provided parameter values.  This method will query the database to discover the parameters for the 
        /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
        /// </summary>
        /// <remarks>
        /// This method provides no access to output parameters or the stored procedure's return value parameter.
        /// 
        /// e.g.:  
        ///  SqlDataReader dr = ExecuteReader(connString, "GetOrders", 24, 36);
        /// </remarks>
        /// <param name="connectionString">A valid connection string for a SqlConnection</param>
        /// <param name="spName">The name of the stored procedure</param>
        /// <param name="parameterValues">An array of objects to be assigned as the input values of the stored procedure</param>
        /// <returns>A SqlDataReader containing the resultset generated by the command</returns>
        public static SqlDataReader ExecuteReader(string connectionString, string spName, params object[] parameterValues)
        {
            if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );
            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );
            
            // If we receive parameter values, we need to figure out where they go
            if ((parameterValues != null) && (parameterValues.Length > 0)) 
            {
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                AssignParameterValues(commandParameters, parameterValues);

                return ExecuteReader(connectionString, CommandType.StoredProcedure, spName, commandParameters);
            }
            else 
            {
                // Otherwise we can just call the SP without params
                return ExecuteReader(connectionString, CommandType.StoredProcedure, spName);
            }
        }

        /// <summary>
        /// Execute a SqlCommand (that returns a resultset and takes no parameters) against the provided SqlConnection. 
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///  SqlDataReader dr = ExecuteReader(conn, CommandType.StoredProcedure, "GetOrders");
        /// </remarks>
        /// <param name="connection">A valid SqlConnection</param>
        /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">The stored procedure name or T-SQL command</param>
        /// <returns>A SqlDataReader containing the resultset generated by the command</returns>
        public static SqlDataReader ExecuteReader(SqlConnection connection, CommandType commandType, string commandText)
        {
            // Pass through the call providing null for the set of SqlParameters
            return ExecuteReader(connection, commandType, commandText, (SqlParameter[])null);
        }

        /// <summary>
        /// Execute a SqlCommand (that returns a resultset) against the specified SqlConnection 
        /// using the provided parameters.
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///  SqlDataReader dr = ExecuteReader(conn, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
        /// </remarks>
        /// <param name="connection">A valid SqlConnection</param>
        /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">The stored procedure name or T-SQL command</param>
        /// <param name="commandParameters">An array of SqlParamters used to execute the command</param>
        /// <returns>A SqlDataReader containing the resultset generated by the command</returns>
        public static SqlDataReader ExecuteReader(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            // Pass through the call to the private overload using a null transaction value and an externally owned connection
            return ExecuteReader(connection, (SqlTransaction)null, commandType, commandText, commandParameters, SqlConnectionOwnership.External);
        }

        /// <summary>
        /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the specified SqlConnection 
        /// using the provided parameter values.  This method will query the database to discover the parameters for the 
        /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
        /// </summary>
        /// <remarks>
        /// This method provides no access to output parameters or the stored procedure's return value parameter.
        /// 
        /// e.g.:  
        ///  SqlDataReader dr = ExecuteReader(conn, "GetOrders", 24, 36);
        /// </remarks>
        /// <param name="connection">A valid SqlConnection</param>
        /// <param name="spName">The name of the stored procedure</param>
        /// <param name="parameterValues">An array of objects to be assigned as the input values of the stored procedure</param>
        /// <returns>A SqlDataReader containing the resultset generated by the command</returns>
        public static SqlDataReader ExecuteReader(SqlConnection connection, string spName, params object[] parameterValues)
        {
            if( connection == null ) throw new ArgumentNullException( "connection" );
            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            // If we receive parameter values, we need to figure out where they go
            if ((parameterValues != null) && (parameterValues.Length > 0)) 
            {
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                AssignParameterValues(commandParameters, parameterValues);

                return ExecuteReader(connection, CommandType.StoredProcedure, spName, commandParameters);
            }
            else 
            {
                // Otherwise we can just call the SP without params
                return ExecuteReader(connection, CommandType.StoredProcedure, spName);
            }
        }

        /// <summary>
        /// Execute a SqlCommand (that returns a resultset and takes no parameters) against the provided SqlTransaction. 
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///  SqlDataReader dr = ExecuteReader(trans, CommandType.StoredProcedure, "GetOrders");
        /// </remarks>
        /// <param name="transaction">A valid SqlTransaction</param>
        /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">The stored procedure name or T-SQL command</param>
        /// <returns>A SqlDataReader containing the resultset generated by the command</returns>
        public static SqlDataReader ExecuteReader(SqlTransaction transaction, CommandType commandType, string commandText)
        {
            // Pass through the call providing null for the set of SqlParameters
            return ExecuteReader(transaction, commandType, commandText, (SqlParameter[])null);
        }

        /// <summary>
        /// Execute a SqlCommand (that returns a resultset) against the specified SqlTransaction
        /// using the provided parameters.
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///   SqlDataReader dr = ExecuteReader(trans, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
        /// </remarks>
        /// <param name="transaction">A valid SqlTransaction</param>
        /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">The stored procedure name or T-SQL command</param>
        /// <param name="commandParameters">An array of SqlParamters used to execute the command</param>
        /// <returns>A SqlDataReader containing the resultset generated by the command</returns>
        public static SqlDataReader ExecuteReader(SqlTransaction transaction, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            if( transaction == null ) throw new ArgumentNullException( "transaction" );
            if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );

            // Pass through to private overload, indicating that the connection is owned by the caller
            return ExecuteReader(transaction.Connection, transaction, commandType, commandText, commandParameters, SqlConnectionOwnership.External);
        }

        /// <summary>
        /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the specified
        /// SqlTransaction using the provided parameter values.  This method will query the database to discover the parameters for the 
        /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
        /// </summary>
        /// <remarks>
        /// This method provides no access to output parameters or the stored procedure's return value parameter.
        /// 
        /// e.g.:  
        ///  SqlDataReader dr = ExecuteReader(trans, "GetOrders", 24, 36);
        /// </remarks>
        /// <param name="transaction">A valid SqlTransaction</param>
        /// <param name="spName">The name of the stored procedure</param>
        /// <param name="parameterValues">An array of objects to be assigned as the input values of the stored procedure</param>
        /// <returns>A SqlDataReader containing the resultset generated by the command</returns>
        public static SqlDataReader ExecuteReader(SqlTransaction transaction, string spName, params object[] parameterValues)
        {
            if( transaction == null ) throw new ArgumentNullException( "transaction" );
            if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );
            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            // If we receive parameter values, we need to figure out where they go
            if ((parameterValues != null) && (parameterValues.Length > 0)) 
            {
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                AssignParameterValues(commandParameters, parameterValues);

                return ExecuteReader(transaction, CommandType.StoredProcedure, spName, commandParameters);
            }
            else 
            {
                // Otherwise we can just call the SP without params
                return ExecuteReader(transaction, CommandType.StoredProcedure, spName);
            }
        }

        #endregion ExecuteReader

        #region ExecuteScalar
        
        /// <summary>
        /// Execute a SqlCommand (that returns a 1x1 resultset and takes no parameters) against the database specified in 
        /// the connection string. 
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///  int orderCount = (int)ExecuteScalar(connString, CommandType.StoredProcedure, "GetOrderCount");
        /// </remarks>
        /// <param name="connectionString">A valid connection string for a SqlConnection</param>
        /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">The stored procedure name or T-SQL command</param>
        /// <returns>An object containing the value in the 1x1 resultset generated by the command</returns>
        public static object ExecuteScalar(string connectionString, CommandType commandType, string commandText)
        {
            // Pass through the call providing null for the set of SqlParameters
            return ExecuteScalar(connectionString, commandType, commandText, (SqlParameter[])null);
        }

        /// <summary>
        /// Execute a SqlCommand (that returns a 1x1 resultset) against the database specified in the connection string 
        /// using the provided parameters.
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///  int orderCount = (int)ExecuteScalar(connString, CommandType.StoredProcedure, "GetOrderCount", new SqlParameter("@prodid", 24));
        /// </remarks>
        /// <param name="connectionString">A valid connection string for a SqlConnection</param>
        /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">The stored procedure name or T-SQL command</param>
        /// <param name="commandParameters">An array of SqlParamters used to execute the command</param>
        /// <returns>An object containing the value in the 1x1 resultset generated by the command</returns>
        public static object ExecuteScalar(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );
            // Create & open a SqlConnection, and dispose of it after we are done
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                connection.Open();

                // Call the overload that takes a connection in place of the connection string
                return ExecuteScalar(connection, commandType, commandText, commandParameters);
            }
        }

        /// <summary>
        /// Execute a stored procedure via a SqlCommand (that returns a 1x1 resultset) against the database specified in 
        /// the connection string using the provided parameter values.  This method will query the database to discover the parameters for the 
        /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
        /// </summary>
        /// <remarks>
        /// This method provides no access to output parameters or the stored procedure's return value parameter.
        /// 
        /// e.g.:  
        ///  int orderCount = (int)ExecuteScalar(connString, "GetOrderCount", 24, 36);
        /// </remarks>
        /// <param name="connectionString">A valid connection string for a SqlConnection</param>
        /// <param name="spName">The name of the stored procedure</param>
        /// <param name="parameterValues">An array of objects to be assigned as the input values of the stored procedure</param>
        /// <returns>An object containing the value in the 1x1 resultset generated by the command</returns>
        public static object ExecuteScalar(string connectionString, string spName, params object[] parameterValues)
        {
            if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );
            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );
            
            // If we receive parameter values, we need to figure out where they go
            if ((parameterValues != null) && (parameterValues.Length > 0)) 
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                // Assign the provided values to these parameters based on parameter order
                AssignParameterValues(commandParameters, parameterValues);

                // Call the overload that takes an array of SqlParameters
                return ExecuteScalar(connectionString, CommandType.StoredProcedure, spName, commandParameters);
            }
            else 
            {
                // Otherwise we can just call the SP without params
                return ExecuteScalar(connectionString, CommandType.StoredProcedure, spName);
            }
        }

        /// <summary>
        /// Execute a SqlCommand (that returns a 1x1 resultset and takes no parameters) against the provided SqlConnection. 
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///  int orderCount = (int)ExecuteScalar(conn, CommandType.StoredProcedure, "GetOrderCount");
        /// </remarks>
        /// <param name="connection">A valid SqlConnection</param>
        /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">The stored procedure name or T-SQL command</param>
        /// <returns>An object containing the value in the 1x1 resultset generated by the command</returns>
        public static object ExecuteScalar(SqlConnection connection, CommandType commandType, string commandText)
        {
            // Pass through the call providing null for the set of SqlParameters
            return ExecuteScalar(connection, commandType, commandText, (SqlParameter[])null);
        }

        /// <summary>
        /// Execute a SqlCommand (that returns a 1x1 resultset) against the specified SqlConnection 
        /// using the provided parameters.
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///  int orderCount = (int)ExecuteScalar(conn, CommandType.StoredProcedure, "GetOrderCount", new SqlParameter("@prodid", 24));
        /// </remarks>
        /// <param name="connection">A valid SqlConnection</param>
        /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">The stored procedure name or T-SQL command</param>
        /// <param name="commandParameters">An array of SqlParamters used to execute the command</param>
        /// <returns>An object containing the value in the 1x1 resultset generated by the command</returns>
        public static object ExecuteScalar(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            if( connection == null ) throw new ArgumentNullException( "connection" );

            // Create a command and prepare it for execution
            SqlCommand cmd = new SqlCommand();

            bool mustCloseConnection = false;
            PrepareCommand(cmd, connection, (SqlTransaction)null, commandType, commandText, commandParameters, out mustCloseConnection );
                
            // Execute the command & return the results
            object retval = cmd.ExecuteScalar();
                
            // Detach the SqlParameters from the command object, so they can be used again
            cmd.Parameters.Clear();

            if( mustCloseConnection )
                connection.Close();

            return retval;
        }

        /// <summary>
        /// Execute a stored procedure via a SqlCommand (that returns a 1x1 resultset) against the specified SqlConnection 
        /// using the provided parameter values.  This method will query the database to discover the parameters for the 
        /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
        /// </summary>
        /// <remarks>
        /// This method provides no access to output parameters or the stored procedure's return value parameter.
        /// 
        /// e.g.:  
        ///  int orderCount = (int)ExecuteScalar(conn, "GetOrderCount", 24, 36);
        /// </remarks>
        /// <param name="connection">A valid SqlConnection</param>
        /// <param name="spName">The name of the stored procedure</param>
        /// <param name="parameterValues">An array of objects to be assigned as the input values of the stored procedure</param>
        /// <returns>An object containing the value in the 1x1 resultset generated by the command</returns>
        public static object ExecuteScalar(SqlConnection connection, string spName, params object[] parameterValues)
        {
            if( connection == null ) throw new ArgumentNullException( "connection" );
            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            // If we receive parameter values, we need to figure out where they go
            if ((parameterValues != null) && (parameterValues.Length > 0)) 
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                // Assign the provided values to these parameters based on parameter order
                AssignParameterValues(commandParameters, parameterValues);

                // Call the overload that takes an array of SqlParameters
                return ExecuteScalar(connection, CommandType.StoredProcedure, spName, commandParameters);
            }
            else 
            {
                // Otherwise we can just call the SP without params
                return ExecuteScalar(connection, CommandType.StoredProcedure, spName);
            }
        }

        /// <summary>
        /// Execute a SqlCommand (that returns a 1x1 resultset and takes no parameters) against the provided SqlTransaction. 
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///  int orderCount = (int)ExecuteScalar(trans, CommandType.StoredProcedure, "GetOrderCount");
        /// </remarks>
        /// <param name="transaction">A valid SqlTransaction</param>
        /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">The stored procedure name or T-SQL command</param>
        /// <returns>An object containing the value in the 1x1 resultset generated by the command</returns>
        public static object ExecuteScalar(SqlTransaction transaction, CommandType commandType, string commandText)
        {
            // Pass through the call providing null for the set of SqlParameters
            return ExecuteScalar(transaction, commandType, commandText, (SqlParameter[])null);
        }

        /// <summary>
        /// Execute a SqlCommand (that returns a 1x1 resultset) against the specified SqlTransaction
        /// using the provided parameters.
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///  int orderCount = (int)ExecuteScalar(trans, CommandType.StoredProcedure, "GetOrderCount", new SqlParameter("@prodid", 24));
        /// </remarks>
        /// <param name="transaction">A valid SqlTransaction</param>
        /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">The stored procedure name or T-SQL command</param>
        /// <param name="commandParameters">An array of SqlParamters used to execute the command</param>
        /// <returns>An object containing the value in the 1x1 resultset generated by the command</returns>
        public static object ExecuteScalar(SqlTransaction transaction, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            if( transaction == null ) throw new ArgumentNullException( "transaction" );
            if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );

            // Create a command and prepare it for execution
            SqlCommand cmd = new SqlCommand();
            bool mustCloseConnection = false;
            PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection );
                
            // Execute the command & return the results
            object retval = cmd.ExecuteScalar();
                
            // Detach the SqlParameters from the command object, so they can be used again
            cmd.Parameters.Clear();
            return retval;
        }

        /// <summary>
        /// Execute a stored procedure via a SqlCommand (that returns a 1x1 resultset) against the specified
        /// SqlTransaction using the provided parameter values.  This method will query the database to discover the parameters for the 
        /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
        /// </summary>
        /// <remarks>
        /// This method provides no access to output parameters or the stored procedure's return value parameter.
        /// 
        /// e.g.:  
        ///  int orderCount = (int)ExecuteScalar(trans, "GetOrderCount", 24, 36);
        /// </remarks>
        /// <param name="transaction">A valid SqlTransaction</param>
        /// <param name="spName">The name of the stored procedure</param>
        /// <param name="parameterValues">An array of objects to be assigned as the input values of the stored procedure</param>
        /// <returns>An object containing the value in the 1x1 resultset generated by the command</returns>
        public static object ExecuteScalar(SqlTransaction transaction, string spName, params object[] parameterValues)
        {
            if( transaction == null ) throw new ArgumentNullException( "transaction" );
            if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );
            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            // If we receive parameter values, we need to figure out where they go
            if ((parameterValues != null) && (parameterValues.Length > 0)) 
            {
                // PPull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                // Assign the provided values to these parameters based on parameter order
                AssignParameterValues(commandParameters, parameterValues);

                // Call the overload that takes an array of SqlParameters
                return ExecuteScalar(transaction, CommandType.StoredProcedure, spName, commandParameters);
            }
            else 
            {
                // Otherwise we can just call the SP without params
                return ExecuteScalar(transaction, CommandType.StoredProcedure, spName);
            }
        }

        #endregion ExecuteScalar    

        #region ExecuteXmlReader
        /// <summary>
        /// Execute a SqlCommand (that returns a resultset and takes no parameters) against the provided SqlConnection. 
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///  XmlReader r = ExecuteXmlReader(conn, CommandType.StoredProcedure, "GetOrders");
        /// </remarks>
        /// <param name="connection">A valid SqlConnection</param>
        /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">The stored procedure name or T-SQL command using "FOR XML AUTO"</param>
        /// <returns>An XmlReader containing the resultset generated by the command</returns>
        public static XmlReader ExecuteXmlReader(SqlConnection connection, CommandType commandType, string commandText)
        {
            // Pass through the call providing null for the set of SqlParameters
            return ExecuteXmlReader(connection, commandType, commandText, (SqlParameter[])null);
        }

        /// <summary>
        /// Execute a SqlCommand (that returns a resultset) against the specified SqlConnection 
        /// using the provided parameters.
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///  XmlReader r = ExecuteXmlReader(conn, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
        /// </remarks>
        /// <param name="connection">A valid SqlConnection</param>
        /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">The stored procedure name or T-SQL command using "FOR XML AUTO"</param>
        /// <param name="commandParameters">An array of SqlParamters used to execute the command</param>
        /// <returns>An XmlReader containing the resultset generated by the command</returns>
        public static XmlReader ExecuteXmlReader(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            if( connection == null ) throw new ArgumentNullException( "connection" );

            bool mustCloseConnection = false;
            // Create a command and prepare it for execution
            SqlCommand cmd = new SqlCommand();
            try
            {
                PrepareCommand(cmd, connection, (SqlTransaction)null, commandType, commandText, commandParameters, out mustCloseConnection );
            
                // Create the DataAdapter & DataSet
                XmlReader retval = cmd.ExecuteXmlReader();
            
                // Detach the SqlParameters from the command object, so they can be used again
                cmd.Parameters.Clear();

                return retval;
            }
            catch
            {    
                if( mustCloseConnection )
                    connection.Close();
                throw;
            }
        }

        /// <summary>
        /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the specified SqlConnection 
        /// using the provided parameter values.  This method will query the database to discover the parameters for the 
        /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
        /// </summary>
        /// <remarks>
        /// This method provides no access to output parameters or the stored procedure's return value parameter.
        /// 
        /// e.g.:  
        ///  XmlReader r = ExecuteXmlReader(conn, "GetOrders", 24, 36);
        /// </remarks>
        /// <param name="connection">A valid SqlConnection</param>
        /// <param name="spName">The name of the stored procedure using "FOR XML AUTO"</param>
        /// <param name="parameterValues">An array of objects to be assigned as the input values of the stored procedure</param>
        /// <returns>An XmlReader containing the resultset generated by the command</returns>
        public static XmlReader ExecuteXmlReader(SqlConnection connection, string spName, params object[] parameterValues)
        {
            if( connection == null ) throw new ArgumentNullException( "connection" );
            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            // If we receive parameter values, we need to figure out where they go
            if ((parameterValues != null) && (parameterValues.Length > 0)) 
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                // Assign the provided values to these parameters based on parameter order
                AssignParameterValues(commandParameters, parameterValues);

                // Call the overload that takes an array of SqlParameters
                return ExecuteXmlReader(connection, CommandType.StoredProcedure, spName, commandParameters);
            }
            else 
            {
                // Otherwise we can just call the SP without params
                return ExecuteXmlReader(connection, CommandType.StoredProcedure, spName);
            }
        }

        /// <summary>
        /// Execute a SqlCommand (that returns a resultset and takes no parameters) against the provided SqlTransaction. 
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///  XmlReader r = ExecuteXmlReader(trans, CommandType.StoredProcedure, "GetOrders");
        /// </remarks>
        /// <param name="transaction">A valid SqlTransaction</param>
        /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">The stored procedure name or T-SQL command using "FOR XML AUTO"</param>
        /// <returns>An XmlReader containing the resultset generated by the command</returns>
        public static XmlReader ExecuteXmlReader(SqlTransaction transaction, CommandType commandType, string commandText)
        {
            // Pass through the call providing null for the set of SqlParameters
            return ExecuteXmlReader(transaction, commandType, commandText, (SqlParameter[])null);
        }

        /// <summary>
        /// Execute a SqlCommand (that returns a resultset) against the specified SqlTransaction
        /// using the provided parameters.
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///  XmlReader r = ExecuteXmlReader(trans, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24));
        /// </remarks>
        /// <param name="transaction">A valid SqlTransaction</param>
        /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">The stored procedure name or T-SQL command using "FOR XML AUTO"</param>
        /// <param name="commandParameters">An array of SqlParamters used to execute the command</param>
        /// <returns>An XmlReader containing the resultset generated by the command</returns>
        public static XmlReader ExecuteXmlReader(SqlTransaction transaction, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
        {
            if( transaction == null ) throw new ArgumentNullException( "transaction" );
            if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );

            // Create a command and prepare it for execution
            SqlCommand cmd = new SqlCommand();
            bool mustCloseConnection = false;
            PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection );
            
            // Create the DataAdapter & DataSet
            XmlReader retval = cmd.ExecuteXmlReader();
            
            // Detach the SqlParameters from the command object, so they can be used again
            cmd.Parameters.Clear();
            return retval;            
        }

        /// <summary>
        /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the specified 
        /// SqlTransaction using the provided parameter values.  This method will query the database to discover the parameters for the 
        /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
        /// </summary>
        /// <remarks>
        /// This method provides no access to output parameters or the stored procedure's return value parameter.
        /// 
        /// e.g.:  
        ///  XmlReader r = ExecuteXmlReader(trans, "GetOrders", 24, 36);
        /// </remarks>
        /// <param name="transaction">A valid SqlTransaction</param>
        /// <param name="spName">The name of the stored procedure</param>
        /// <param name="parameterValues">An array of objects to be assigned as the input values of the stored procedure</param>
        /// <returns>A dataset containing the resultset generated by the command</returns>
        public static XmlReader ExecuteXmlReader(SqlTransaction transaction, string spName, params object[] parameterValues)
        {
            if( transaction == null ) throw new ArgumentNullException( "transaction" );
            if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );
            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            // If we receive parameter values, we need to figure out where they go
            if ((parameterValues != null) && (parameterValues.Length > 0)) 
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                // Assign the provided values to these parameters based on parameter order
                AssignParameterValues(commandParameters, parameterValues);

                // Call the overload that takes an array of SqlParameters
                return ExecuteXmlReader(transaction, CommandType.StoredProcedure, spName, commandParameters);
            }
            else 
            {
                // Otherwise we can just call the SP without params
                return ExecuteXmlReader(transaction, CommandType.StoredProcedure, spName);
            }
        }

        #endregion ExecuteXmlReader

        #region FillDataset
        /// <summary>
        /// Execute a SqlCommand (that returns a resultset and takes no parameters) against the database specified in 
        /// the connection string. 
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///  FillDataset(connString, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"});
        /// </remarks>
        /// <param name="connectionString">A valid connection string for a SqlConnection</param>
        /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">The stored procedure name or T-SQL command</param>
        /// <param name="dataSet">A dataset wich will contain the resultset generated by the command</param>
        /// <param name="tableNames">This array will be used to create table mappings allowing the DataTables to be referenced
        /// by a user defined name (probably the actual table name)</param>
        public static void FillDataset(string connectionString, CommandType commandType, string commandText, DataSet dataSet, string[] tableNames)
        {
            if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );
            if( dataSet == null ) throw new ArgumentNullException( "dataSet" );
            
            // Create & open a SqlConnection, and dispose of it after we are done
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                connection.Open();

                // Call the overload that takes a connection in place of the connection string
                FillDataset(connection, commandType, commandText, dataSet, tableNames);
            }
        }

        /// <summary>
        /// Execute a SqlCommand (that returns a resultset) against the database specified in the connection string 
        /// using the provided parameters.
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///  FillDataset(connString, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}, new SqlParameter("@prodid", 24));
        /// </remarks>
        /// <param name="connectionString">A valid connection string for a SqlConnection</param>
        /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">The stored procedure name or T-SQL command</param>
        /// <param name="commandParameters">An array of SqlParamters used to execute the command</param>
        /// <param name="dataSet">A dataset wich will contain the resultset generated by the command</param>
        /// <param name="tableNames">This array will be used to create table mappings allowing the DataTables to be referenced
        /// by a user defined name (probably the actual table name)
        /// </param>
        public static void FillDataset(string connectionString, CommandType commandType,
            string commandText, DataSet dataSet, string[] tableNames,
            params SqlParameter[] commandParameters)
        {
            if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );
            if( dataSet == null ) throw new ArgumentNullException( "dataSet" );
            // Create & open a SqlConnection, and dispose of it after we are done
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                connection.Open();

                // Call the overload that takes a connection in place of the connection string
                FillDataset(connection, commandType, commandText, dataSet, tableNames, commandParameters);
            }
        }

        /// <summary>
        /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the database specified in 
        /// the connection string using the provided parameter values.  This method will query the database to discover the parameters for the 
        /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
        /// </summary>
        /// <remarks>
        /// This method provides no access to output parameters or the stored procedure's return value parameter.
        /// 
        /// e.g.:  
        ///  FillDataset(connString, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}, 24);
        /// </remarks>
        /// <param name="connectionString">A valid connection string for a SqlConnection</param>
        /// <param name="spName">The name of the stored procedure</param>
        /// <param name="dataSet">A dataset wich will contain the resultset generated by the command</param>
        /// <param name="tableNames">This array will be used to create table mappings allowing the DataTables to be referenced
        /// by a user defined name (probably the actual table name)
        /// </param>    
        /// <param name="parameterValues">An array of objects to be assigned as the input values of the stored procedure</param>
        public static void FillDataset(string connectionString, string spName,
            DataSet dataSet, string[] tableNames,
            params object[] parameterValues)
        {
            if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );
            if( dataSet == null ) throw new ArgumentNullException( "dataSet" );
            // Create & open a SqlConnection, and dispose of it after we are done
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                connection.Open();

                // Call the overload that takes a connection in place of the connection string
                FillDataset (connection, spName, dataSet, tableNames, parameterValues);
            }
        }

        /// <summary>
        /// Execute a SqlCommand (that returns a resultset and takes no parameters) against the provided SqlConnection. 
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///  FillDataset(conn, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"});
        /// </remarks>
        /// <param name="connection">A valid SqlConnection</param>
        /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">The stored procedure name or T-SQL command</param>
        /// <param name="dataSet">A dataset wich will contain the resultset generated by the command</param>
        /// <param name="tableNames">This array will be used to create table mappings allowing the DataTables to be referenced
        /// by a user defined name (probably the actual table name)
        /// </param>    
        public static void FillDataset(SqlConnection connection, CommandType commandType, 
            string commandText, DataSet dataSet, string[] tableNames)
        {
            FillDataset(connection, commandType, commandText, dataSet, tableNames, null);
        }

        /// <summary>
        /// Execute a SqlCommand (that returns a resultset) against the specified SqlConnection 
        /// using the provided parameters.
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///  FillDataset(conn, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}, new SqlParameter("@prodid", 24));
        /// </remarks>
        /// <param name="connection">A valid SqlConnection</param>
        /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">The stored procedure name or T-SQL command</param>
        /// <param name="dataSet">A dataset wich will contain the resultset generated by the command</param>
        /// <param name="tableNames">This array will be used to create table mappings allowing the DataTables to be referenced
        /// by a user defined name (probably the actual table name)
        /// </param>
        /// <param name="commandParameters">An array of SqlParamters used to execute the command</param>
        public static void FillDataset(SqlConnection connection, CommandType commandType, 
            string commandText, DataSet dataSet, string[] tableNames,
            params SqlParameter[] commandParameters)
        {
            FillDataset(connection, null, commandType, commandText, dataSet, tableNames, commandParameters);
        }

        /// <summary>
        /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the specified SqlConnection 
        /// using the provided parameter values.  This method will query the database to discover the parameters for the 
        /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
        /// </summary>
        /// <remarks>
        /// This method provides no access to output parameters or the stored procedure's return value parameter.
        /// 
        /// e.g.:  
        ///  FillDataset(conn, "GetOrders", ds, new string[] {"orders"}, 24, 36);
        /// </remarks>
        /// <param name="connection">A valid SqlConnection</param>
        /// <param name="spName">The name of the stored procedure</param>
        /// <param name="dataSet">A dataset wich will contain the resultset generated by the command</param>
        /// <param name="tableNames">This array will be used to create table mappings allowing the DataTables to be referenced
        /// by a user defined name (probably the actual table name)
        /// </param>
        /// <param name="parameterValues">An array of objects to be assigned as the input values of the stored procedure</param>
        public static void FillDataset(SqlConnection connection, string spName, 
            DataSet dataSet, string[] tableNames,
            params object[] parameterValues)
        {
            if ( connection == null ) throw new ArgumentNullException( "connection" );
            if (dataSet == null ) throw new ArgumentNullException( "dataSet" );
            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            // If we receive parameter values, we need to figure out where they go
            if ((parameterValues != null) && (parameterValues.Length > 0)) 
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                // Assign the provided values to these parameters based on parameter order
                AssignParameterValues(commandParameters, parameterValues);

                // Call the overload that takes an array of SqlParameters
                FillDataset(connection, CommandType.StoredProcedure, spName, dataSet, tableNames, commandParameters);
            }
            else 
            {
                // Otherwise we can just call the SP without params
                FillDataset(connection, CommandType.StoredProcedure, spName, dataSet, tableNames);
            }    
        }

        /// <summary>
        /// Execute a SqlCommand (that returns a resultset and takes no parameters) against the provided SqlTransaction. 
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///  FillDataset(trans, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"});
        /// </remarks>
        /// <param name="transaction">A valid SqlTransaction</param>
        /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">The stored procedure name or T-SQL command</param>
        /// <param name="dataSet">A dataset wich will contain the resultset generated by the command</param>
        /// <param name="tableNames">This array will be used to create table mappings allowing the DataTables to be referenced
        /// by a user defined name (probably the actual table name)
        /// </param>
        public static void FillDataset(SqlTransaction transaction, CommandType commandType, 
            string commandText,
            DataSet dataSet, string[] tableNames)
        {
            FillDataset (transaction, commandType, commandText, dataSet, tableNames, null);    
        }

        /// <summary>
        /// Execute a SqlCommand (that returns a resultset) against the specified SqlTransaction
        /// using the provided parameters.
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///  FillDataset(trans, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}, new SqlParameter("@prodid", 24));
        /// </remarks>
        /// <param name="transaction">A valid SqlTransaction</param>
        /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">The stored procedure name or T-SQL command</param>
        /// <param name="dataSet">A dataset wich will contain the resultset generated by the command</param>
        /// <param name="tableNames">This array will be used to create table mappings allowing the DataTables to be referenced
        /// by a user defined name (probably the actual table name)
        /// </param>
        /// <param name="commandParameters">An array of SqlParamters used to execute the command</param>
        public static void FillDataset(SqlTransaction transaction, CommandType commandType, 
            string commandText, DataSet dataSet, string[] tableNames,
            params SqlParameter[] commandParameters)
        {
            FillDataset(transaction.Connection, transaction, commandType, commandText, dataSet, tableNames, commandParameters);
        }

        /// <summary>
        /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the specified 
        /// SqlTransaction using the provided parameter values.  This method will query the database to discover the parameters for the 
        /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
        /// </summary>
        /// <remarks>
        /// This method provides no access to output parameters or the stored procedure's return value parameter.
        /// 
        /// e.g.:  
        ///  FillDataset(trans, "GetOrders", ds, new string[]{"orders"}, 24, 36);
        /// </remarks>
        /// <param name="transaction">A valid SqlTransaction</param>
        /// <param name="spName">The name of the stored procedure</param>
        /// <param name="dataSet">A dataset wich will contain the resultset generated by the command</param>
        /// <param name="tableNames">This array will be used to create table mappings allowing the DataTables to be referenced
        /// by a user defined name (probably the actual table name)
        /// </param>
        /// <param name="parameterValues">An array of objects to be assigned as the input values of the stored procedure</param>
        public static void FillDataset(SqlTransaction transaction, string spName,
            DataSet dataSet, string[] tableNames,
            params object[] parameterValues) 
        {
            if( transaction == null ) throw new ArgumentNullException( "transaction" );
            if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );
            if( dataSet == null ) throw new ArgumentNullException( "dataSet" );
            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            // If we receive parameter values, we need to figure out where they go
            if ((parameterValues != null) && (parameterValues.Length > 0)) 
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                // Assign the provided values to these parameters based on parameter order
                AssignParameterValues(commandParameters, parameterValues);

                // Call the overload that takes an array of SqlParameters
                FillDataset(transaction, CommandType.StoredProcedure, spName, dataSet, tableNames, commandParameters);
            }
            else 
            {
                // Otherwise we can just call the SP without params
                FillDataset(transaction, CommandType.StoredProcedure, spName, dataSet, tableNames);
            }    
        }

        /// <summary>
        /// Private helper method that execute a SqlCommand (that returns a resultset) against the specified SqlTransaction and SqlConnection
        /// using the provided parameters.
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///  FillDataset(conn, trans, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}, new SqlParameter("@prodid", 24));
        /// </remarks>
        /// <param name="connection">A valid SqlConnection</param>
        /// <param name="transaction">A valid SqlTransaction</param>
        /// <param name="commandType">The CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">The stored procedure name or T-SQL command</param>
        /// <param name="dataSet">A dataset wich will contain the resultset generated by the command</param>
        /// <param name="tableNames">This array will be used to create table mappings allowing the DataTables to be referenced
        /// by a user defined name (probably the actual table name)
        /// </param>
        /// <param name="commandParameters">An array of SqlParamters used to execute the command</param>
        private static void FillDataset(SqlConnection connection, SqlTransaction transaction, CommandType commandType, 
            string commandText, DataSet dataSet, string[] tableNames,
            params SqlParameter[] commandParameters)
        {
            if( connection == null ) throw new ArgumentNullException( "connection" );
            if( dataSet == null ) throw new ArgumentNullException( "dataSet" );

            // Create a command and prepare it for execution
            SqlCommand command = new SqlCommand();
            bool mustCloseConnection = false;
            PrepareCommand(command, connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection );
                
            // Create the DataAdapter & DataSet
            using( SqlDataAdapter dataAdapter = new SqlDataAdapter(command) )
            {
                
                // Add the table mappings specified by the user
                if (tableNames != null && tableNames.Length > 0)
                {
                    string tableName = "Table";
                    for (int index=0; index < tableNames.Length; index++)
                    {
                        if( tableNames[index] == null || tableNames[index].Length == 0 ) throw new ArgumentException( "The tableNames parameter must contain a list of tables, a value was provided as null or empty string.", "tableNames" );
                        dataAdapter.TableMappings.Add(tableName, tableNames[index]);
                        tableName += (index + 1).ToString();
                    }
                }
                
                // Fill the DataSet using default values for DataTable names, etc
                dataAdapter.Fill(dataSet);

                // Detach the SqlParameters from the command object, so they can be used again
                command.Parameters.Clear();
            }

            if( mustCloseConnection )
                connection.Close();
        }
        #endregion
        
        #region UpdateDataset
        /// <summary>
        /// Executes the respective command for each inserted, updated, or deleted row in the DataSet.
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///  UpdateDataset(conn, insertCommand, deleteCommand, updateCommand, dataSet, "Order");
        /// </remarks>
        /// <param name="insertCommand">A valid transact-SQL statement or stored procedure to insert new records into the data source</param>
        /// <param name="deleteCommand">A valid transact-SQL statement or stored procedure to delete records from the data source</param>
        /// <param name="updateCommand">A valid transact-SQL statement or stored procedure used to update records in the data source</param>
        /// <param name="dataSet">The DataSet used to update the data source</param>
        /// <param name="tableName">The DataTable used to update the data source.</param>
        public static void UpdateDataset(SqlCommand insertCommand, SqlCommand deleteCommand, SqlCommand updateCommand, DataSet dataSet, string tableName)
        {
            if( insertCommand == null ) throw new ArgumentNullException( "insertCommand" );
            if( deleteCommand == null ) throw new ArgumentNullException( "deleteCommand" );
            if( updateCommand == null ) throw new ArgumentNullException( "updateCommand" );
            if( tableName == null || tableName.Length == 0 ) throw new ArgumentNullException( "tableName" ); 

            // Create a SqlDataAdapter, and dispose of it after we are done
            using (SqlDataAdapter dataAdapter = new SqlDataAdapter())
            {
                // Set the data adapter commands
                dataAdapter.UpdateCommand = updateCommand;
                dataAdapter.InsertCommand = insertCommand;
                dataAdapter.DeleteCommand = deleteCommand;

                // Update the dataset changes in the data source
                dataAdapter.Update (dataSet, tableName); 

                // Commit all the changes made to the DataSet
                dataSet.AcceptChanges();
            }
        }
        #endregion

        #region CreateCommand
        /// <summary>
        /// Simplify the creation of a Sql command object by allowing
        /// a stored procedure and optional parameters to be provided
        /// </summary>
        /// <remarks>
        /// e.g.:  
        ///  SqlCommand command = CreateCommand(conn, "AddCustomer", "CustomerID", "CustomerName");
        /// </remarks>
        /// <param name="connection">A valid SqlConnection object</param>
        /// <param name="spName">The name of the stored procedure</param>
        /// <param name="sourceColumns">An array of string to be assigned as the source columns of the stored procedure parameters</param>
        /// <returns>A valid SqlCommand object</returns>
        public static SqlCommand CreateCommand(SqlConnection connection, string spName, params string[] sourceColumns) 
        {
            if( connection == null ) throw new ArgumentNullException( "connection" );
            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            // Create a SqlCommand
            SqlCommand cmd = new SqlCommand( spName, connection );
            cmd.CommandType = CommandType.StoredProcedure;

            // If we receive parameter values, we need to figure out where they go
            if ((sourceColumns != null) && (sourceColumns.Length > 0)) 
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                // Assign the provided source columns to these parameters based on parameter order
                for (int index=0; index < sourceColumns.Length; index++)
                    commandParameters[index].SourceColumn = sourceColumns[index];

                // Attach the discovered parameters to the SqlCommand object
                AttachParameters (cmd, commandParameters);
            }

            return cmd;
        }
        #endregion

        #region ExecuteNonQueryTypedParams
        /// <summary>
        /// Execute a stored procedure via a SqlCommand (that returns no resultset) against the database specified in 
        /// the connection string using the dataRow column values as the stored procedure's parameters values.
        /// This method will query the database to discover the parameters for the 
        /// stored procedure (the first time each stored procedure is called), and assign the values based on row values.
        /// </summary>
        /// <param name="connectionString">A valid connection string for a SqlConnection</param>
        /// <param name="spName">The name of the stored procedure</param>
        /// <param name="dataRow">The dataRow used to hold the stored procedure's parameter values.</param>
        /// <returns>An int representing the number of rows affected by the command</returns>
        public static int ExecuteNonQueryTypedParams(String connectionString, String spName, DataRow dataRow)
        {
            if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );
            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );
            
            // If the row has values, the store procedure parameters must be initialized
            if (dataRow != null && dataRow.ItemArray.Length > 0)
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);
                
                // Set the parameters values
                AssignParameterValues(commandParameters, dataRow);
                                
                return SqlHelper.ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return SqlHelper.ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName);
            }
        }

        /// <summary>
        /// Execute a stored procedure via a SqlCommand (that returns no resultset) against the specified SqlConnection 
        /// using the dataRow column values as the stored procedure's parameters values.  
        /// This method will query the database to discover the parameters for the 
        /// stored procedure (the first time each stored procedure is called), and assign the values based on row values.
        /// </summary>
        /// <param name="connection">A valid SqlConnection object</param>
        /// <param name="spName">The name of the stored procedure</param>
        /// <param name="dataRow">The dataRow used to hold the stored procedure's parameter values.</param>
        /// <returns>An int representing the number of rows affected by the command</returns>
        public static int ExecuteNonQueryTypedParams(SqlConnection connection, String spName, DataRow dataRow)
        {
            if( connection == null ) throw new ArgumentNullException( "connection" );
            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            // If the row has values, the store procedure parameters must be initialized
            if (dataRow != null && dataRow.ItemArray.Length > 0)
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);
                
                // Set the parameters values
                AssignParameterValues(commandParameters, dataRow);
                                
                return SqlHelper.ExecuteNonQuery(connection, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return SqlHelper.ExecuteNonQuery(connection, CommandType.StoredProcedure, spName);
            }
        }

        /// <summary>
        /// Execute a stored procedure via a SqlCommand (that returns no resultset) against the specified
        /// SqlTransaction using the dataRow column values as the stored procedure's parameters values.
        /// This method will query the database to discover the parameters for the 
        /// stored procedure (the first time each stored procedure is called), and assign the values based on row values.
        /// </summary>
        /// <param name="transaction">A valid SqlTransaction object</param>
        /// <param name="spName">The name of the stored procedure</param>
        /// <param name="dataRow">The dataRow used to hold the stored procedure's parameter values.</param>
        /// <returns>An int representing the number of rows affected by the command</returns>
        public static int ExecuteNonQueryTypedParams(SqlTransaction transaction, String spName, DataRow dataRow)
        {
            if( transaction == null ) throw new ArgumentNullException( "transaction" );
            if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );
            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            // Sf the row has values, the store procedure parameters must be initialized
            if (dataRow != null && dataRow.ItemArray.Length > 0)
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);
                
                // Set the parameters values
                AssignParameterValues(commandParameters, dataRow);
                                
                return SqlHelper.ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return SqlHelper.ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName);
            }
        }
        #endregion

        #region ExecuteDatasetTypedParams
        /// <summary>
        /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the database specified in 
        /// the connection string using the dataRow column values as the stored procedure's parameters values.
        /// This method will query the database to discover the parameters for the 
        /// stored procedure (the first time each stored procedure is called), and assign the values based on row values.
        /// </summary>
        /// <param name="connectionString">A valid connection string for a SqlConnection</param>
        /// <param name="spName">The name of the stored procedure</param>
        /// <param name="dataRow">The dataRow used to hold the stored procedure's parameter values.</param>
        /// <returns>A dataset containing the resultset generated by the command</returns>
        public static DataSet ExecuteDatasetTypedParams(string connectionString, String spName, DataRow dataRow)
        {
            if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );
            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            //If the row has values, the store procedure parameters must be initialized
            if ( dataRow != null && dataRow.ItemArray.Length > 0)
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);
                
                // Set the parameters values
                AssignParameterValues(commandParameters, dataRow);
                
                return SqlHelper.ExecuteDataset(connectionString, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return SqlHelper.ExecuteDataset(connectionString, CommandType.StoredProcedure, spName);
            }
        }

        /// <summary>
        /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the specified SqlConnection 
        /// using the dataRow column values as the store procedure's parameters values.
        /// This method will query the database to discover the parameters for the 
        /// stored procedure (the first time each stored procedure is called), and assign the values based on row values.
        /// </summary>
        /// <param name="connection">A valid SqlConnection object</param>
        /// <param name="spName">The name of the stored procedure</param>
        /// <param name="dataRow">The dataRow used to hold the stored procedure's parameter values.</param>
        /// <returns>A dataset containing the resultset generated by the command</returns>
        public static DataSet ExecuteDatasetTypedParams(SqlConnection connection, String spName, DataRow dataRow)
        {
            if( connection == null ) throw new ArgumentNullException( "connection" );
            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            // If the row has values, the store procedure parameters must be initialized
            if( dataRow != null && dataRow.ItemArray.Length > 0)
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);
                
                // Set the parameters values
                AssignParameterValues(commandParameters, dataRow);
                
                return SqlHelper.ExecuteDataset(connection, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return SqlHelper.ExecuteDataset(connection, CommandType.StoredProcedure, spName);
            }
        }

        /// <summary>
        /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the specified SqlTransaction 
        /// using the dataRow column values as the stored procedure's parameters values.
        /// This method will query the database to discover the parameters for the 
        /// stored procedure (the first time each stored procedure is called), and assign the values based on row values.
        /// </summary>
        /// <param name="transaction">A valid SqlTransaction object</param>
        /// <param name="spName">The name of the stored procedure</param>
        /// <param name="dataRow">The dataRow used to hold the stored procedure's parameter values.</param>
        /// <returns>A dataset containing the resultset generated by the command</returns>
        public static DataSet ExecuteDatasetTypedParams(SqlTransaction transaction, String spName, DataRow dataRow)
        {
            if( transaction == null ) throw new ArgumentNullException( "transaction" );
            if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );
            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            // If the row has values, the store procedure parameters must be initialized
            if( dataRow != null && dataRow.ItemArray.Length > 0)
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);
                
                // Set the parameters values
                AssignParameterValues(commandParameters, dataRow);
                
                return SqlHelper.ExecuteDataset(transaction, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return SqlHelper.ExecuteDataset(transaction, CommandType.StoredProcedure, spName);
            }
        }

        #endregion

        #region ExecuteReaderTypedParams
        /// <summary>
        /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the database specified in 
        /// the connection string using the dataRow column values as the stored procedure's parameters values.
        /// This method will query the database to discover the parameters for the 
        /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
        /// </summary>
        /// <param name="connectionString">A valid connection string for a SqlConnection</param>
        /// <param name="spName">The name of the stored procedure</param>
        /// <param name="dataRow">The dataRow used to hold the stored procedure's parameter values.</param>
        /// <returns>A SqlDataReader containing the resultset generated by the command</returns>
        public static SqlDataReader ExecuteReaderTypedParams(String connectionString, String spName, DataRow dataRow)
        {
            if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );
            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );
            
            // If the row has values, the store procedure parameters must be initialized
            if ( dataRow != null && dataRow.ItemArray.Length > 0 )
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);
                
                // Set the parameters values
                AssignParameterValues(commandParameters, dataRow);
                
                return SqlHelper.ExecuteReader(connectionString, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return SqlHelper.ExecuteReader(connectionString, CommandType.StoredProcedure, spName);
            }
        }

                
        /// <summary>
        /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the specified SqlConnection 
        /// using the dataRow column values as the stored procedure's parameters values.
        /// This method will query the database to discover the parameters for the 
        /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
        /// </summary>
        /// <param name="connection">A valid SqlConnection object</param>
        /// <param name="spName">The name of the stored procedure</param>
        /// <param name="dataRow">The dataRow used to hold the stored procedure's parameter values.</param>
        /// <returns>A SqlDataReader containing the resultset generated by the command</returns>
        public static SqlDataReader ExecuteReaderTypedParams(SqlConnection connection, String spName, DataRow dataRow)
        {
            if( connection == null ) throw new ArgumentNullException( "connection" );
            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            // If the row has values, the store procedure parameters must be initialized
            if( dataRow != null && dataRow.ItemArray.Length > 0)
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);
                
                // Set the parameters values
                AssignParameterValues(commandParameters, dataRow);
                
                return SqlHelper.ExecuteReader(connection, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return SqlHelper.ExecuteReader(connection, CommandType.StoredProcedure, spName);
            }
        }
        
        /// <summary>
        /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the specified SqlTransaction 
        /// using the dataRow column values as the stored procedure's parameters values.
        /// This method will query the database to discover the parameters for the 
        /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
        /// </summary>
        /// <param name="transaction">A valid SqlTransaction object</param>
        /// <param name="spName">The name of the stored procedure</param>
        /// <param name="dataRow">The dataRow used to hold the stored procedure's parameter values.</param>
        /// <returns>A SqlDataReader containing the resultset generated by the command</returns>
        public static SqlDataReader ExecuteReaderTypedParams(SqlTransaction transaction, String spName, DataRow dataRow)
        {
            if( transaction == null ) throw new ArgumentNullException( "transaction" );
            if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );
            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            // If the row has values, the store procedure parameters must be initialized
            if( dataRow != null && dataRow.ItemArray.Length > 0 )
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);
                
                // Set the parameters values
                AssignParameterValues(commandParameters, dataRow);
                
                return SqlHelper.ExecuteReader(transaction, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return SqlHelper.ExecuteReader(transaction, CommandType.StoredProcedure, spName);
            }
        }
        #endregion

        #region ExecuteScalarTypedParams
        /// <summary>
        /// Execute a stored procedure via a SqlCommand (that returns a 1x1 resultset) against the database specified in 
        /// the connection string using the dataRow column values as the stored procedure's parameters values.
        /// This method will query the database to discover the parameters for the 
        /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
        /// </summary>
        /// <param name="connectionString">A valid connection string for a SqlConnection</param>
        /// <param name="spName">The name of the stored procedure</param>
        /// <param name="dataRow">The dataRow used to hold the stored procedure's parameter values.</param>
        /// <returns>An object containing the value in the 1x1 resultset generated by the command</returns>
        public static object ExecuteScalarTypedParams(String connectionString, String spName, DataRow dataRow)
        {
            if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );
            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );
            
            // If the row has values, the store procedure parameters must be initialized
            if( dataRow != null && dataRow.ItemArray.Length > 0)
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);
                
                // Set the parameters values
                AssignParameterValues(commandParameters, dataRow);
                
                return SqlHelper.ExecuteScalar(connectionString, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return SqlHelper.ExecuteScalar(connectionString, CommandType.StoredProcedure, spName);
            }
        }

        /// <summary>
        /// Execute a stored procedure via a SqlCommand (that returns a 1x1 resultset) against the specified SqlConnection 
        /// using the dataRow column values as the stored procedure's parameters values.
        /// This method will query the database to discover the parameters for the 
        /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
        /// </summary>
        /// <param name="connection">A valid SqlConnection object</param>
        /// <param name="spName">The name of the stored procedure</param>
        /// <param name="dataRow">The dataRow used to hold the stored procedure's parameter values.</param>
        /// <returns>An object containing the value in the 1x1 resultset generated by the command</returns>
        public static object ExecuteScalarTypedParams(SqlConnection connection, String spName, DataRow dataRow)
        {
            if( connection == null ) throw new ArgumentNullException( "connection" );
            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            // If the row has values, the store procedure parameters must be initialized
            if( dataRow != null && dataRow.ItemArray.Length > 0)
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);
                
                // Set the parameters values
                AssignParameterValues(commandParameters, dataRow);
                
                return SqlHelper.ExecuteScalar(connection, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return SqlHelper.ExecuteScalar(connection, CommandType.StoredProcedure, spName);
            }
        }

        /// <summary>
        /// Execute a stored procedure via a SqlCommand (that returns a 1x1 resultset) against the specified SqlTransaction
        /// using the dataRow column values as the stored procedure's parameters values.
        /// This method will query the database to discover the parameters for the 
        /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
        /// </summary>
        /// <param name="transaction">A valid SqlTransaction object</param>
        /// <param name="spName">The name of the stored procedure</param>
        /// <param name="dataRow">The dataRow used to hold the stored procedure's parameter values.</param>
        /// <returns>An object containing the value in the 1x1 resultset generated by the command</returns>
        public static object ExecuteScalarTypedParams(SqlTransaction transaction, String spName, DataRow dataRow)
        {
            if( transaction == null ) throw new ArgumentNullException( "transaction" );
            if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );
            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            // If the row has values, the store procedure parameters must be initialized
            if( dataRow != null && dataRow.ItemArray.Length > 0)
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);
                
                // Set the parameters values
                AssignParameterValues(commandParameters, dataRow);
                
                return SqlHelper.ExecuteScalar(transaction, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return SqlHelper.ExecuteScalar(transaction, CommandType.StoredProcedure, spName);
            }
        }
        #endregion

        #region ExecuteXmlReaderTypedParams
        /// <summary>
        /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the specified SqlConnection 
        /// using the dataRow column values as the stored procedure's parameters values.
        /// This method will query the database to discover the parameters for the 
        /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
        /// </summary>
        /// <param name="connection">A valid SqlConnection object</param>
        /// <param name="spName">The name of the stored procedure</param>
        /// <param name="dataRow">The dataRow used to hold the stored procedure's parameter values.</param>
        /// <returns>An XmlReader containing the resultset generated by the command</returns>
        public static XmlReader ExecuteXmlReaderTypedParams(SqlConnection connection, String spName, DataRow dataRow)
        {
            if( connection == null ) throw new ArgumentNullException( "connection" );
            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            // If the row has values, the store procedure parameters must be initialized
            if( dataRow != null && dataRow.ItemArray.Length > 0)
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);
                
                // Set the parameters values
                AssignParameterValues(commandParameters, dataRow);
                
                return SqlHelper.ExecuteXmlReader(connection, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return SqlHelper.ExecuteXmlReader(connection, CommandType.StoredProcedure, spName);
            }
        }

        /// <summary>
        /// Execute a stored procedure via a SqlCommand (that returns a resultset) against the specified SqlTransaction 
        /// using the dataRow column values as the stored procedure's parameters values.
        /// This method will query the database to discover the parameters for the 
        /// stored procedure (the first time each stored procedure is called), and assign the values based on parameter order.
        /// </summary>
        /// <param name="transaction">A valid SqlTransaction object</param>
        /// <param name="spName">The name of the stored procedure</param>
        /// <param name="dataRow">The dataRow used to hold the stored procedure's parameter values.</param>
        /// <returns>An XmlReader containing the resultset generated by the command</returns>
        public static XmlReader ExecuteXmlReaderTypedParams(SqlTransaction transaction, String spName, DataRow dataRow)
        {
            if( transaction == null ) throw new ArgumentNullException( "transaction" );
            if( transaction != null && transaction.Connection == null ) throw new ArgumentException( "The transaction was rollbacked or commited, please provide an open transaction.", "transaction" );
            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            // If the row has values, the store procedure parameters must be initialized
            if( dataRow != null && dataRow.ItemArray.Length > 0)
            {
                // Pull the parameters for this stored procedure from the parameter cache (or discover them & populate the cache)
                SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);
                
                // Set the parameters values
                AssignParameterValues(commandParameters, dataRow);
                
                return SqlHelper.ExecuteXmlReader(transaction, CommandType.StoredProcedure, spName, commandParameters);
            }
            else
            {
                return SqlHelper.ExecuteXmlReader(transaction, CommandType.StoredProcedure, spName);
            }
        }
        #endregion

    }

    /// <summary>
    /// SqlHelperParameterCache provides functions to leverage a static cache of procedure parameters, and the
    /// ability to discover parameters for stored procedures at run-time.
    /// </summary>
    public sealed class SqlHelperParameterCache
    {
        #region private methods, variables, and constructors

        //Since this class provides only static methods, make the default constructor private to prevent 
        //instances from being created with "new SqlHelperParameterCache()"
        private SqlHelperParameterCache() {}

        private static Hashtable paramCache = Hashtable.Synchronized(new Hashtable());

        /// <summary>
        /// Resolve at run time the appropriate set of SqlParameters for a stored procedure
        /// </summary>
        /// <param name="connection">A valid SqlConnection object</param>
        /// <param name="spName">The name of the stored procedure</param>
        /// <param name="includeReturnValueParameter">Whether or not to include their return value parameter</param>
        /// <returns>The parameter array discovered.</returns>
        private static SqlParameter[] DiscoverSpParameterSet(SqlConnection connection, string spName, bool includeReturnValueParameter)
        {
            if( connection == null ) throw new ArgumentNullException( "connection" );
            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            SqlCommand cmd = new SqlCommand(spName, connection);
            cmd.CommandType = CommandType.StoredProcedure;

            connection.Open();
            SqlCommandBuilder.DeriveParameters(cmd);
            connection.Close();

            if (!includeReturnValueParameter) 
            {
                cmd.Parameters.RemoveAt(0);
            }
                
            SqlParameter[] discoveredParameters = new SqlParameter[cmd.Parameters.Count];

            cmd.Parameters.CopyTo(discoveredParameters, 0);

            // Init the parameters with a DBNull value
            foreach (SqlParameter discoveredParameter in discoveredParameters)
            {
                discoveredParameter.Value = DBNull.Value;
            }
            return discoveredParameters;
        }

        /// <summary>
        /// Deep copy of cached SqlParameter array
        /// </summary>
        /// <param name="originalParameters"></param>
        /// <returns></returns>
        private static SqlParameter[] CloneParameters(SqlParameter[] originalParameters)
        {
            SqlParameter[] clonedParameters = new SqlParameter[originalParameters.Length];

            for (int i = 0, j = originalParameters.Length; i < j; i++)
            {
                clonedParameters[i] = (SqlParameter)((ICloneable)originalParameters[i]).Clone();
            }

            return clonedParameters;
        }

        #endregion private methods, variables, and constructors

        #region caching functions

        /// <summary>
        /// Add parameter array to the cache
        /// </summary>
        /// <param name="connectionString">A valid connection string for a SqlConnection</param>
        /// <param name="commandText">The stored procedure name or T-SQL command</param>
        /// <param name="commandParameters">An array of SqlParamters to be cached</param>
        public static void CacheParameterSet(string connectionString, string commandText, params SqlParameter[] commandParameters)
        {
            if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );
            if( commandText == null || commandText.Length == 0 ) throw new ArgumentNullException( "commandText" );

            string hashKey = connectionString + ":" + commandText;

            paramCache[hashKey] = commandParameters;
        }

        /// <summary>
        /// Retrieve a parameter array from the cache
        /// </summary>
        /// <param name="connectionString">A valid connection string for a SqlConnection</param>
        /// <param name="commandText">The stored procedure name or T-SQL command</param>
        /// <returns>An array of SqlParamters</returns>
        public static SqlParameter[] GetCachedParameterSet(string connectionString, string commandText)
        {
            if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );
            if( commandText == null || commandText.Length == 0 ) throw new ArgumentNullException( "commandText" );

            string hashKey = connectionString + ":" + commandText;

            SqlParameter[] cachedParameters = paramCache[hashKey] as SqlParameter[];
            if (cachedParameters == null)
            {            
                return null;
            }
            else
            {
                return CloneParameters(cachedParameters);
            }
        }

        #endregion caching functions

        #region Parameter Discovery Functions

        /// <summary>
        /// Retrieves the set of SqlParameters appropriate for the stored procedure
        /// </summary>
        /// <remarks>
        /// This method will query the database for this information, and then store it in a cache for future requests.
        /// </remarks>
        /// <param name="connectionString">A valid connection string for a SqlConnection</param>
        /// <param name="spName">The name of the stored procedure</param>
        /// <returns>An array of SqlParameters</returns>
        public static SqlParameter[] GetSpParameterSet(string connectionString, string spName)
        {
            return GetSpParameterSet(connectionString, spName, false);
        }

        /// <summary>
        /// Retrieves the set of SqlParameters appropriate for the stored procedure
        /// </summary>
        /// <remarks>
        /// This method will query the database for this information, and then store it in a cache for future requests.
        /// </remarks>
        /// <param name="connectionString">A valid connection string for a SqlConnection</param>
        /// <param name="spName">The name of the stored procedure</param>
        /// <param name="includeReturnValueParameter">A bool value indicating whether the return value parameter should be included in the results</param>
        /// <returns>An array of SqlParameters</returns>
        public static SqlParameter[] GetSpParameterSet(string connectionString, string spName, bool includeReturnValueParameter)
        {
            if( connectionString == null || connectionString.Length == 0 ) throw new ArgumentNullException( "connectionString" );
            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            using(SqlConnection connection = new SqlConnection(connectionString))
            {
                return GetSpParameterSetInternal(connection, spName, includeReturnValueParameter);
            }
        }

        /// <summary>
        /// Retrieves the set of SqlParameters appropriate for the stored procedure
        /// </summary>
        /// <remarks>
        /// This method will query the database for this information, and then store it in a cache for future requests.
        /// </remarks>
        /// <param name="connection">A valid SqlConnection object</param>
        /// <param name="spName">The name of the stored procedure</param>
        /// <returns>An array of SqlParameters</returns>
        internal static SqlParameter[] GetSpParameterSet(SqlConnection connection, string spName)
        {
            return GetSpParameterSet(connection, spName, false);
        }

        /// <summary>
        /// Retrieves the set of SqlParameters appropriate for the stored procedure
        /// </summary>
        /// <remarks>
        /// This method will query the database for this information, and then store it in a cache for future requests.
        /// </remarks>
        /// <param name="connection">A valid SqlConnection object</param>
        /// <param name="spName">The name of the stored procedure</param>
        /// <param name="includeReturnValueParameter">A bool value indicating whether the return value parameter should be included in the results</param>
        /// <returns>An array of SqlParameters</returns>
        internal static SqlParameter[] GetSpParameterSet(SqlConnection connection, string spName, bool includeReturnValueParameter)
        {
            if( connection == null ) throw new ArgumentNullException( "connection" );
            using (SqlConnection clonedConnection = (SqlConnection)((ICloneable)connection).Clone())
            {
                return GetSpParameterSetInternal(clonedConnection, spName, includeReturnValueParameter);
            }
        }

        /// <summary>
        /// Retrieves the set of SqlParameters appropriate for the stored procedure
        /// </summary>
        /// <param name="connection">A valid SqlConnection object</param>
        /// <param name="spName">The name of the stored procedure</param>
        /// <param name="includeReturnValueParameter">A bool value indicating whether the return value parameter should be included in the results</param>
        /// <returns>An array of SqlParameters</returns>
        private static SqlParameter[] GetSpParameterSetInternal(SqlConnection connection, string spName, bool includeReturnValueParameter)
        {
            if( connection == null ) throw new ArgumentNullException( "connection" );
            if( spName == null || spName.Length == 0 ) throw new ArgumentNullException( "spName" );

            string hashKey = connection.ConnectionString + ":" + spName + (includeReturnValueParameter ? ":include ReturnValue Parameter":"");

            SqlParameter[] cachedParameters;
            
            cachedParameters = paramCache[hashKey] as SqlParameter[];
            if (cachedParameters == null)
            {    
                SqlParameter[] spParameters = DiscoverSpParameterSet(connection, spName, includeReturnValueParameter);
                paramCache[hashKey] = spParameters;
                cachedParameters = spParameters;
            }
            
            return CloneParameters(cachedParameters);
        }
        /// <summary>
        /// 清空缓存参数
        /// </summary>
        public static void  ClearCache()
        {
            paramCache.Clear();
        }
        #endregion Parameter Discovery Functions

    }
}