SQLHelper类如何实现数据库操作？ 程序员

之前一直用网上搜集并进行修改的数据库操作类，之后找了这个微软的SQLHelper类，确实很强大。两者对比，自己也还没有总结出哪些异点，快2两年的时间没有项目开发了，脑子里的编程都生锈了，只好重零开始，找回最初的状态。

自己的DBHelper类

public class DBHelper
    {
        /// <summary>
        /// 从Web.config配置文件中读取数据库连接
        /// </summary>
        private static string connectionStrings = ConfigurationManager.ConnectionStrings["MyConnectionString"].ToString();

        public static string ConnectionStrings
        {
            get { return DBHelper.connectionStrings; }
        }
        /// <summary>
        /// 打开数据库连接
        /// </summary>
        /// <param name="cmdText"></param>
        /// <param name="cmdType"></param>
        /// <param name="param"></param>
        /// <returns></returns>
        private static SqlCommand GetCommand(string strSql, CommandType cmdType, SqlParameter[] parameters)
        {
            SqlCommand cmd = new SqlCommand();
            cmd.Connection = new SqlConnection(connectionStrings);//连接配置文件
            try
            {
                cmd.CommandText = strSql;//传入SQL语句或存储过程
                cmd.CommandType = cmdType;// 
                if (parameters != null)
                {
                    foreach (SqlParameter p in parameters)
                    {
                        cmd.Parameters.Add(p);
                    }
                }
            }
            finally
            {
                cmd.Connection.Open();//打开连接
            }

            return cmd;
        }

        /// <summary>
        /// 返回受影响的行数
        /// </summary>
        /// <param name="cmdText"></param>
        /// <param name="cmdType"></param>
        /// <param name="param"></param>
        /// <returns></returns>
        public static int ExecuteQuery(string strSql, CommandType cmdType, params SqlParameter[] param)
        {
            SqlCommand cmd = GetCommand(strSql, cmdType, param);
            int result = 0;
            try
            {
                result = cmd.ExecuteNonQuery();
            }
            finally
            {
                cmd.Connection.Close();
            }
            return result;
        }
        /// <summary>
        /// 返回一行一列
        /// </summary>
        /// <param name="cmdText"></param>
        /// <param name="cmdType"></param>
        /// <param name="param"></param>
        /// <returns></returns>
        public static int ExecuteScalar(string strSql, CommandType cmdType, params SqlParameter[] param)
        {
            SqlCommand cmd = GetCommand(strSql, cmdType, param);
            int result = 0;
            try
            {
                result = (int)cmd.ExecuteScalar();
            }
            finally
            {
                cmd.Connection.Close();
            }
            return result;
        }

        /// <summary>
        /// 返回集合(dataSet)
        /// </summary>
        /// <param name="cmdText"></param>
        /// <param name="cmdType"></param>
        /// <param name="param"></param>
        /// <returns></returns>
        public static DataSet ExecuteDataSet(string strSql, CommandType cmdType, params SqlParameter[] parameters)
        {
            DataSet ds = new DataSet();
            
            SqlCommand cmd = GetCommand(strSql, cmdType, parameters);
            try
            {
                SqlDataAdapter adapter = new SqlDataAdapter(cmd);
                adapter.Fill(ds);
            }
            finally
            {
                cmd.Connection.Close();//关闭连接
            }
            return ds;
        }

        /// <summary>
        /// 返回某个对象(dataTable)
        /// </summary>
        /// <param name="cmdText"></param>
        /// <param name="cmdType"></param>
        /// <param name="param"></param>
        /// <returns></returns>
        public static DataTable ExecuteDataTable(string strSql, CommandType cmdType, params SqlParameter[] parameters)
        {
            SqlCommand cmd = GetCommand(strSql, cmdType, parameters);
            DataSet ds = new DataSet();
            try
            {
                SqlDataAdapter adapter = new SqlDataAdapter(cmd);
                adapter.Fill(ds);
            }
            finally
            {
                cmd.Connection.Close();
            }
            return ds.Tables[0];
        }
    }

SQLHelper类代码

public class SQLHelper
    {
        /// <summary> 
        /// SqlServer数据访问帮助类 
        /// </summary> 
        public sealed class SqlHelper
        {
            #region 私有构造函数和方法

            private SqlHelper() { }

            /// <summary> 
            /// 将SqlParameter参数数组(参数值)分配给SqlCommand命令. 
            /// 这个方法将给任何一个参数分配DBNull.Value; 
            /// 该操作将阻止默认值的使用. 
            /// </summary> 
            /// <param name="command">命令名</param> 
            /// <param name="commandParameters">SqlParameters数组</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)
                        {
                            // 检查未分配值的输出参数,将其分配以DBNull.Value. 
                            if ((p.Direction == ParameterDirection.InputOutput || p.Direction == ParameterDirection.Input) &&
                                (p.Value == null))
                            {
                                p.Value = DBNull.Value;
                            }
                            command.Parameters.Add(p);
                        }
                    }
                }
            }

            /// <summary> 
            /// 将DataRow类型的列值分配到SqlParameter参数数组. 
            /// </summary> 
            /// <param name="commandParameters">要分配值的SqlParameter参数数组</param> 
            /// <param name="dataRow">将要分配给存储过程参数的DataRow</param> 
            private static void AssignParameterValues(SqlParameter[] commandParameters, DataRow dataRow)
            {
                if ((commandParameters == null) || (dataRow == null))
                {
                    return;
                }

                int i = 0;
                // 设置参数值 
                foreach (SqlParameter commandParameter in commandParameters)
                {
                    // 创建参数名称,如果不存在,只抛出一个异常. 
                    if (commandParameter.ParameterName == null ||
                        commandParameter.ParameterName.Length <= 1)
                        throw new Exception(
                            string.Format("请提供参数{0}一个有效的名称{1}.", i, commandParameter.ParameterName));
                    // 从dataRow的表中获取为参数数组中数组名称的列的索引. 
                    // 如果存在和参数名称相同的列,则将列值赋给当前名称的参数. 
                    if (dataRow.Table.Columns.IndexOf(commandParameter.ParameterName.Substring(1)) != -1)
                        commandParameter.Value = dataRow[commandParameter.ParameterName.Substring(1)];
                    i++;
                }
            }

            /// <summary> 
            /// 将一个对象数组分配给SqlParameter参数数组. 
            /// </summary> 
            /// <param name="commandParameters">要分配值的SqlParameter参数数组</param> 
            /// <param name="parameterValues">将要分配给存储过程参数的对象数组</param> 
            private static void AssignParameterValues(SqlParameter[] commandParameters, object[] parameterValues)
            {
                if ((commandParameters == null) || (parameterValues == null))
                {
                    return;
                }

                // 确保对象数组个数与参数个数匹配,如果不匹配,抛出一个异常. 
                if (commandParameters.Length != parameterValues.Length)
                {
                    throw new ArgumentException("参数值个数与参数不匹配.");
                }

                // 给参数赋值 
                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> 
            /// 预处理用户提供的命令,数据库连接/事务/命令类型/参数 
            /// </summary> 
            /// <param name="command">要处理的SqlCommand</param> 
            /// <param name="connection">数据库连接</param> 
            /// <param name="transaction">一个有效的事务或者是null值</param> 
            /// <param name="commandType">命令类型 (存储过程,命令文本, 其它.)</param> 
            /// <param name="commandText">存储过程名或都T-SQL命令文本</param> 
            /// <param name="commandParameters">和命令相关联的SqlParameter参数数组,如果没有参数为'null'</param> 
            /// <param name="mustCloseConnection"><c>true</c> 如果连接是打开的,则为true,其它情况下为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;
                }

                // 给命令分配一个数据库连接. 
                command.Connection = connection;

                // 设置命令文本(存储过程名或SQL语句) 
                command.CommandText = commandText;

                // 分配事务 
                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;
                }

                // 设置命令类型. 
                command.CommandType = commandType;

                // 分配命令参数 
                if (commandParameters != null)
                {
                    AttachParameters(command, commandParameters);
                }
                return;
            }

            #endregion 私有构造函数和方法结束

            #region 数据库连接
            /// <summary> 
            /// 一个有效的数据库连接字符串 
            /// </summary> 
            /// <returns></returns> 
            public static string GetConnSting()
            {
                return ConfigurationManager.ConnectionStrings["MyConnectionString"].ConnectionString;
            }
            /// <summary> 
            /// 一个有效的数据库连接对象 
            /// </summary> 
            /// <returns></returns> 
            public static SqlConnection GetConnection()
            {
                SqlConnection Connection = new SqlConnection(SqlHelper.GetConnSting());
                return Connection;
            }
            #endregion

            #region ExecuteNonQuery命令

            /// <summary> 
            /// 执行指定连接字符串,类型的SqlCommand. 
            /// </summary> 
            /// <remarks> 
            /// 示例:  
            ///  int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders"); 
            /// </remarks> 
            /// <param name="connectionString">一个有效的数据库连接字符串</param> 
            /// <param name="commandType">命令类型 (存储过程,命令文本, 其它.)</param> 
            /// <param name="commandText">存储过程名称或SQL语句</param> 
            /// <returns>返回命令影响的行数</returns> 
            public static int ExecuteNonQuery(string connectionString, CommandType commandType, string commandText)
            {
                return ExecuteNonQuery(connectionString, commandType, commandText, (SqlParameter[])null);
            }

            /// <summary> 
            /// 执行指定连接字符串,类型的SqlCommand.如果没有提供参数,不返回结果. 
            /// </summary> 
            /// <remarks> 
            /// 示例:  
            ///  int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24)); 
            /// </remarks> 
            /// <param name="connectionString">一个有效的数据库连接字符串</param> 
            /// <param name="commandType">命令类型 (存储过程,命令文本, 其它.)</param> 
            /// <param name="commandText">存储过程名称或SQL语句</param> 
            /// <param name="commandParameters">SqlParameter参数数组</param> 
            /// <returns>返回命令影响的行数</returns> 
            public static int ExecuteNonQuery(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
            {
                if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");

                using (SqlConnection connection = new SqlConnection(connectionString))
                {
                    connection.Open();

                    return ExecuteNonQuery(connection, commandType, commandText, commandParameters);
                }
            }

            /// <summary> 
            /// 执行指定连接字符串的存储过程,将对象数组的值赋给存储过程参数, 
            /// 此方法需要在参数缓存方法中探索参数并生成参数. 
            /// </summary> 
            /// <remarks> 
            /// 这个方法没有提供访问输出参数和返回值. 
            /// 示例:  
            ///  int result = ExecuteNonQuery(connString, "PublishOrders", 24, 36); 
            /// </remarks> 
            /// <param name="connectionString">一个有效的数据库连接字符串/param> 
            /// <param name="spName">存储过程名称</param> 
            /// <param name="parameterValues">分配到存储过程输入参数的对象数组</param> 
            /// <returns>返回受影响的行数</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");

                // 如果存在参数值 
                if ((parameterValues != null) && (parameterValues.Length > 0))
                {
                    // 从探索存储过程参数(加载到缓存)并分配给存储过程参数数组. 
                    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                    // 给存储过程参数赋值 
                    AssignParameterValues(commandParameters, parameterValues);

                    return ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    // 没有参数情况下 
                    return ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName);
                }
            }

            /// <summary> 
            /// 执行指定数据库连接对象的命令 
            /// </summary> 
            /// <remarks> 
            /// 示例:  
            ///  int result = ExecuteNonQuery(conn, CommandType.StoredProcedure, "PublishOrders"); 
            /// </remarks> 
            /// <param name="connection">一个有效的数据库连接对象</param> 
            /// <param name="commandType">命令类型(存储过程,命令文本或其它.)</param> 
            /// <param name="commandText">存储过程名称或T-SQL语句</param> 
            /// <returns>返回影响的行数</returns> 
            public static int ExecuteNonQuery(SqlConnection connection, CommandType commandType, string commandText)
            {
                return ExecuteNonQuery(connection, commandType, commandText, (SqlParameter[])null);
            }

            /// <summary> 
            /// 执行指定数据库连接对象的命令 
            /// </summary> 
            /// <remarks> 
            /// 示例:  
            ///  int result = ExecuteNonQuery(conn, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24)); 
            /// </remarks> 
            /// <param name="connection">一个有效的数据库连接对象</param> 
            /// <param name="commandType">命令类型(存储过程,命令文本或其它.)</param> 
            /// <param name="commandText">T存储过程名称或T-SQL语句</param> 
            /// <param name="commandParameters">SqlParamter参数数组</param> 
            /// <returns>返回影响的行数</returns> 
            public static int ExecuteNonQuery(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
            {
                if (connection == null) throw new ArgumentNullException("connection");

                // 创建SqlCommand命令,并进行预处理 
                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();

                // 清除参数,以便再次使用. 
                cmd.Parameters.Clear();
                if (mustCloseConnection)
                    connection.Close();
                return retval;
            }

            /// <summary> 
            /// 执行指定数据库连接对象的命令,将对象数组的值赋给存储过程参数. 
            /// </summary> 
            /// <remarks> 
            /// 此方法不提供访问存储过程输出参数和返回值 
            /// 示例:  
            ///  int result = ExecuteNonQuery(conn, "PublishOrders", 24, 36); 
            /// </remarks> 
            /// <param name="connection">一个有效的数据库连接对象</param> 
            /// <param name="spName">存储过程名</param> 
            /// <param name="parameterValues">分配给存储过程输入参数的对象数组</param> 
            /// <returns>返回影响的行数</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");

                // 如果有参数值 
                if ((parameterValues != null) && (parameterValues.Length > 0))
                {
                    // 从缓存中加载存储过程参数 
                    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                    // 给存储过程分配参数值 
                    AssignParameterValues(commandParameters, parameterValues);

                    return ExecuteNonQuery(connection, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    return ExecuteNonQuery(connection, CommandType.StoredProcedure, spName);
                }
            }

            /// <summary> 
            /// 执行带事务的SqlCommand. 
            /// </summary> 
            /// <remarks> 
            /// 示例.:  
            ///  int result = ExecuteNonQuery(trans, CommandType.StoredProcedure, "PublishOrders"); 
            /// </remarks> 
            /// <param name="transaction">一个有效的数据库连接对象</param> 
            /// <param name="commandType">命令类型(存储过程,命令文本或其它.)</param> 
            /// <param name="commandText">存储过程名称或T-SQL语句</param> 
            /// <returns>返回影响的行数/returns> 
            public static int ExecuteNonQuery(SqlTransaction transaction, CommandType commandType, string commandText)
            {
                return ExecuteNonQuery(transaction, commandType, commandText, (SqlParameter[])null);
            }

            /// <summary> 
            /// 执行带事务的SqlCommand(指定参数). 
            /// </summary> 
            /// <remarks> 
            /// 示例:  
            ///  int result = ExecuteNonQuery(trans, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24)); 
            /// </remarks> 
            /// <param name="transaction">一个有效的数据库连接对象</param> 
            /// <param name="commandType">命令类型(存储过程,命令文本或其它.)</param> 
            /// <param name="commandText">存储过程名称或T-SQL语句</param> 
            /// <param name="commandParameters">SqlParamter参数数组</param> 
            /// <returns>返回影响的行数</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");

                // 预处理 
                SqlCommand cmd = new SqlCommand();
                bool mustCloseConnection = false;
                PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection);

                // 执行 
                int retval = cmd.ExecuteNonQuery();

                // 清除参数集,以便再次使用. 
                cmd.Parameters.Clear();
                return retval;
            }

            /// <summary> 
            /// 执行带事务的SqlCommand(指定参数值). 
            /// </summary> 
            /// <remarks> 
            /// 此方法不提供访问存储过程输出参数和返回值 
            /// 示例:  
            ///  int result = ExecuteNonQuery(conn, trans, "PublishOrders", 24, 36); 
            /// </remarks> 
            /// <param name="transaction">一个有效的数据库连接对象</param> 
            /// <param name="spName">存储过程名</param> 
            /// <param name="parameterValues">分配给存储过程输入参数的对象数组</param> 
            /// <returns>返回受影响的行数</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");

                // 如果有参数值 
                if ((parameterValues != null) && (parameterValues.Length > 0))
                {
                    // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
                    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                    // 给存储过程参数赋值 
                    AssignParameterValues(commandParameters, parameterValues);

                    // 调用重载方法 
                    return ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    // 没有参数值 
                    return ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName);
                }
            }

            #endregion ExecuteNonQuery方法结束

            #region ExecuteDataset方法

            /// <summary> 
            /// 执行指定数据库连接字符串的命令,返回DataSet. 
            /// </summary> 
            /// <remarks> 
            /// 示例:  
            ///  DataSet ds = ExecuteDataset(connString, CommandType.StoredProcedure, "GetOrders"); 
            /// </remarks> 
            /// <param name="connectionString">一个有效的数据库连接字符串</param> 
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
            /// <param name="commandText">存储过程名称或T-SQL语句</param> 
            /// <returns>返回一个包含结果集的DataSet</returns> 
            public static DataSet ExecuteDataset(string connectionString, CommandType commandType, string commandText)
            {
                return ExecuteDataset(connectionString, commandType, commandText, (SqlParameter[])null);
            }

            /// <summary> 
            /// 执行指定数据库连接字符串的命令,返回DataSet. 
            /// </summary> 
            /// <remarks> 
            /// 示例: 
            ///  DataSet ds = ExecuteDataset(connString, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24)); 
            /// </remarks> 
            /// <param name="connectionString">一个有效的数据库连接字符串</param> 
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
            /// <param name="commandText">存储过程名称或T-SQL语句</param> 
            /// <param name="commandParameters">SqlParamters参数数组</param> 
            /// <returns>返回一个包含结果集的DataSet</returns> 
            public static DataSet ExecuteDataset(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
            {
                if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");

                // 创建并打开数据库连接对象,操作完成释放对象. 
                using (SqlConnection connection = new SqlConnection(connectionString))
                {
                    connection.Open();

                    // 调用指定数据库连接字符串重载方法. 
                    return ExecuteDataset(connection, commandType, commandText, commandParameters);
                }
            }

            /// <summary> 
            /// 执行指定数据库连接字符串的命令,直接提供参数值,返回DataSet. 
            /// </summary> 
            /// <remarks> 
            /// 此方法不提供访问存储过程输出参数和返回值. 
            /// 示例: 
            ///  DataSet ds = ExecuteDataset(connString, "GetOrders", 24, 36); 
            /// </remarks> 
            /// <param name="connectionString">一个有效的数据库连接字符串</param> 
            /// <param name="spName">存储过程名</param> 
            /// <param name="parameterValues">分配给存储过程输入参数的对象数组</param> 
            /// <returns>返回一个包含结果集的DataSet</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 ((parameterValues != null) && (parameterValues.Length > 0))
                {
                    // 从缓存中检索存储过程参数 
                    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                    // 给存储过程参数分配值 
                    AssignParameterValues(commandParameters, parameterValues);

                    return ExecuteDataset(connectionString, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    return ExecuteDataset(connectionString, CommandType.StoredProcedure, spName);
                }
            }

            /// <summary> 
            /// 执行指定数据库连接对象的命令,返回DataSet. 
            /// </summary> 
            /// <remarks> 
            /// 示例:  
            ///  DataSet ds = ExecuteDataset(conn, CommandType.StoredProcedure, "GetOrders"); 
            /// </remarks> 
            /// <param name="connection">一个有效的数据库连接对象</param> 
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
            /// <param name="commandText">存储过程名或T-SQL语句</param> 
            /// <returns>返回一个包含结果集的DataSet</returns> 
            public static DataSet ExecuteDataset(SqlConnection connection, CommandType commandType, string commandText)
            {
                return ExecuteDataset(connection, commandType, commandText, (SqlParameter[])null);
            }

            /// <summary> 
            /// 执行指定数据库连接对象的命令,指定存储过程参数,返回DataSet. 
            /// </summary> 
            /// <remarks> 
            /// 示例:  
            ///  DataSet ds = ExecuteDataset(conn, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24)); 
            /// </remarks> 
            /// <param name="connection">一个有效的数据库连接对象</param> 
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
            /// <param name="commandText">存储过程名或T-SQL语句</param> 
            /// <param name="commandParameters">SqlParamter参数数组</param> 
            /// <returns>返回一个包含结果集的DataSet</returns> 
            public static DataSet ExecuteDataset(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
            {
                if (connection == null) throw new ArgumentNullException("connection");

                // 预处理 
                SqlCommand cmd = new SqlCommand();
                bool mustCloseConnection = false;
                PrepareCommand(cmd, connection, (SqlTransaction)null, commandType, commandText, commandParameters, out mustCloseConnection);

                // 创建SqlDataAdapter和DataSet. 
                using (SqlDataAdapter da = new SqlDataAdapter(cmd))
                {
                    DataSet ds = new DataSet();

                    // 填充DataSet. 
                    da.Fill(ds);

                    cmd.Parameters.Clear();

                    if (mustCloseConnection)
                        connection.Close();

                    return ds;
                }
            }

            /// <summary> 
            /// 执行指定数据库连接对象的命令,指定参数值,返回DataSet. 
            /// </summary> 
            /// <remarks> 
            /// 此方法不提供访问存储过程输入参数和返回值. 
            /// 示例.:  
            ///  DataSet ds = ExecuteDataset(conn, "GetOrders", 24, 36); 
            /// </remarks> 
            /// <param name="connection">一个有效的数据库连接对象</param> 
            /// <param name="spName">存储过程名</param> 
            /// <param name="parameterValues">分配给存储过程输入参数的对象数组</param> 
            /// <returns>返回一个包含结果集的DataSet</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 ((parameterValues != null) && (parameterValues.Length > 0))
                {
                    // 比缓存中加载存储过程参数 
                    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                    // 给存储过程参数分配值 
                    AssignParameterValues(commandParameters, parameterValues);

                    return ExecuteDataset(connection, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    return ExecuteDataset(connection, CommandType.StoredProcedure, spName);
                }
            }

            /// <summary> 
            /// 执行指定事务的命令,返回DataSet. 
            /// </summary> 
            /// <remarks> 
            /// 示例:  
            ///  DataSet ds = ExecuteDataset(trans, CommandType.StoredProcedure, "GetOrders"); 
            /// </remarks> 
            /// <param name="transaction">事务</param> 
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
            /// <param name="commandText">存储过程名或T-SQL语句</param> 
            /// <returns>返回一个包含结果集的DataSet</returns> 
            public static DataSet ExecuteDataset(SqlTransaction transaction, CommandType commandType, string commandText)
            {
                return ExecuteDataset(transaction, commandType, commandText, (SqlParameter[])null);
            }

            /// <summary> 
            /// 执行指定事务的命令,指定参数,返回DataSet. 
            /// </summary> 
            /// <remarks> 
            /// 示例:  
            ///  DataSet ds = ExecuteDataset(trans, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24)); 
            /// </remarks> 
            /// <param name="transaction">事务</param> 
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
            /// <param name="commandText">存储过程名或T-SQL语句</param> 
            /// <param name="commandParameters">SqlParamter参数数组</param> 
            /// <returns>返回一个包含结果集的DataSet</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");

                // 预处理 
                SqlCommand cmd = new SqlCommand();
                bool mustCloseConnection = false;
                PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection);

                // 创建 DataAdapter & DataSet 
                using (SqlDataAdapter da = new SqlDataAdapter(cmd))
                {
                    DataSet ds = new DataSet();
                    da.Fill(ds);
                    cmd.Parameters.Clear();
                    return ds;
                }
            }

            /// <summary> 
            /// 执行指定事务的命令,指定参数值,返回DataSet. 
            /// </summary> 
            /// <remarks> 
            /// 此方法不提供访问存储过程输入参数和返回值. 
            /// 示例.:  
            ///  DataSet ds = ExecuteDataset(trans, "GetOrders", 24, 36); 
            /// </remarks> 
            /// <param name="transaction">事务</param> 
            /// <param name="spName">存储过程名</param> 
            /// <param name="parameterValues">分配给存储过程输入参数的对象数组</param> 
            /// <returns>返回一个包含结果集的DataSet</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 ((parameterValues != null) && (parameterValues.Length > 0))
                {
                    // 从缓存中加载存储过程参数 
                    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                    // 给存储过程参数分配值 
                    AssignParameterValues(commandParameters, parameterValues);

                    return ExecuteDataset(transaction, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    return ExecuteDataset(transaction, CommandType.StoredProcedure, spName);
                }
            }

            #endregion ExecuteDataset数据集命令结束

            #region ExecuteReader 数据阅读器

            /// <summary> 
            /// 枚举,标识数据库连接是由SqlHelper提供还是由调用者提供 
            /// </summary> 
            private enum SqlConnectionOwnership
            {
                /// <summary>由SqlHelper提供连接</summary> 
                Internal,
                /// <summary>由调用者提供连接</summary> 
                External
            }

            /// <summary> 
            /// 执行指定数据库连接对象的数据阅读器. 
            /// </summary> 
            /// <remarks> 
            /// 如果是SqlHelper打开连接,当连接关闭DataReader也将关闭. 
            /// 如果是调用都打开连接,DataReader由调用都管理. 
            /// </remarks> 
            /// <param name="connection">一个有效的数据库连接对象</param> 
            /// <param name="transaction">一个有效的事务,或者为 'null'</param> 
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
            /// <param name="commandText">存储过程名或T-SQL语句</param> 
            /// <param name="commandParameters">SqlParameters参数数组,如果没有参数则为'null'</param> 
            /// <param name="connectionOwnership">标识数据库连接对象是由调用者提供还是由SqlHelper提供</param> 
            /// <returns>返回包含结果集的SqlDataReader</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;
                // 创建命令 
                SqlCommand cmd = new SqlCommand();
                try
                {
                    PrepareCommand(cmd, connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection);

                    // 创建数据阅读器 
                    SqlDataReader dataReader;

                    if (connectionOwnership == SqlConnectionOwnership.External)
                    {
                        dataReader = cmd.ExecuteReader();
                    }
                    else
                    {
                        dataReader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
                    }

                    // 清除参数,以便再次使用.. 
                    // 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> 
            /// 执行指定数据库连接字符串的数据阅读器. 
            /// </summary> 
            /// <remarks> 
            /// 示例:  
            ///  SqlDataReader dr = ExecuteReader(connString, CommandType.StoredProcedure, "GetOrders"); 
            /// </remarks> 
            /// <param name="connectionString">一个有效的数据库连接字符串</param> 
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
            /// <param name="commandText">存储过程名或T-SQL语句</param> 
            /// <returns>返回包含结果集的SqlDataReader</returns> 
            public static SqlDataReader ExecuteReader(string connectionString, CommandType commandType, string commandText)
            {
                return ExecuteReader(connectionString, commandType, commandText, (SqlParameter[])null);
            }

            /// <summary> 
            /// 执行指定数据库连接字符串的数据阅读器,指定参数. 
            /// </summary> 
            /// <remarks> 
            /// 示例:  
            ///  SqlDataReader dr = ExecuteReader(connString, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24)); 
            /// </remarks> 
            /// <param name="connectionString">一个有效的数据库连接字符串</param> 
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
            /// <param name="commandText">存储过程名或T-SQL语句</param> 
            /// <param name="commandParameters">SqlParamter参数数组(new SqlParameter("@prodid", 24))</param> 
            /// <returns>返回包含结果集的SqlDataReader</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();

                    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> 
            /// 执行指定数据库连接字符串的数据阅读器,指定参数值. 
            /// </summary> 
            /// <remarks> 
            /// 此方法不提供访问存储过程输出参数和返回值参数. 
            /// 示例:  
            ///  SqlDataReader dr = ExecuteReader(connString, "GetOrders", 24, 36); 
            /// </remarks> 
            /// <param name="connectionString">一个有效的数据库连接字符串</param> 
            /// <param name="spName">存储过程名</param> 
            /// <param name="parameterValues">分配给存储过程输入参数的对象数组</param> 
            /// <returns>返回包含结果集的SqlDataReader</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 ((parameterValues != null) && (parameterValues.Length > 0))
                {
                    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                    AssignParameterValues(commandParameters, parameterValues);

                    return ExecuteReader(connectionString, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    return ExecuteReader(connectionString, CommandType.StoredProcedure, spName);
                }
            }

            /// <summary> 
            /// 执行指定数据库连接对象的数据阅读器. 
            /// </summary> 
            /// <remarks> 
            /// 示例:  
            ///  SqlDataReader dr = ExecuteReader(conn, CommandType.StoredProcedure, "GetOrders"); 
            /// </remarks> 
            /// <param name="connection">一个有效的数据库连接对象</param> 
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
            /// <param name="commandText">存储过程名或T-SQL语句</param> 
            /// <returns>返回包含结果集的SqlDataReader</returns> 
            public static SqlDataReader ExecuteReader(SqlConnection connection, CommandType commandType, string commandText)
            {
                return ExecuteReader(connection, commandType, commandText, (SqlParameter[])null);
            }

            /// <summary> 
            /// [调用者方式]执行指定数据库连接对象的数据阅读器,指定参数. 
            /// </summary> 
            /// <remarks> 
            /// 示例:  
            ///  SqlDataReader dr = ExecuteReader(conn, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24)); 
            /// </remarks> 
            /// <param name="connection">一个有效的数据库连接对象</param> 
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
            /// <param name="commandText">命令类型 (存储过程,命令文本或其它)</param> 
            /// <param name="commandParameters">SqlParamter参数数组</param> 
            /// <returns>返回包含结果集的SqlDataReader</returns> 
            public static SqlDataReader ExecuteReader(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
            {
                return ExecuteReader(connection, (SqlTransaction)null, commandType, commandText, commandParameters, SqlConnectionOwnership.External);
            }

            /// <summary> 
            /// [调用者方式]执行指定数据库连接对象的数据阅读器,指定参数值. 
            /// </summary> 
            /// <remarks> 
            /// 此方法不提供访问存储过程输出参数和返回值参数. 
            /// 示例:  
            ///  SqlDataReader dr = ExecuteReader(conn, "GetOrders", 24, 36); 
            /// </remarks> 
            /// <param name="connection">一个有效的数据库连接对象</param> 
            /// <param name="spName">T存储过程名</param> 
            /// <param name="parameterValues">分配给存储过程输入参数的对象数组</param> 
            /// <returns>返回包含结果集的SqlDataReader</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 ((parameterValues != null) && (parameterValues.Length > 0))
                {
                    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                    AssignParameterValues(commandParameters, parameterValues);

                    return ExecuteReader(connection, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    return ExecuteReader(connection, CommandType.StoredProcedure, spName);
                }
            }

            /// <summary> 
            /// [调用者方式]执行指定数据库事务的数据阅读器,指定参数值. 
            /// </summary> 
            /// <remarks> 
            /// 示例:  
            ///  SqlDataReader dr = ExecuteReader(trans, CommandType.StoredProcedure, "GetOrders"); 
            /// </remarks> 
            /// <param name="transaction">一个有效的连接事务</param> 
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
            /// <param name="commandText">存储过程名称或T-SQL语句</param> 
            /// <returns>返回包含结果集的SqlDataReader</returns> 
            public static SqlDataReader ExecuteReader(SqlTransaction transaction, CommandType commandType, string commandText)
            {
                return ExecuteReader(transaction, commandType, commandText, (SqlParameter[])null);
            }

            /// <summary> 
            /// [调用者方式]执行指定数据库事务的数据阅读器,指定参数. 
            /// </summary> 
            /// <remarks> 
            /// 示例:  
            ///   SqlDataReader dr = ExecuteReader(trans, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24)); 
            /// </remarks> 
            /// <param name="transaction">一个有效的连接事务</param> 
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
            /// <param name="commandText">存储过程名称或T-SQL语句</param> 
            /// <param name="commandParameters">分配给命令的SqlParamter参数数组</param> 
            /// <returns>返回包含结果集的SqlDataReader</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");

                return ExecuteReader(transaction.Connection, transaction, commandType, commandText, commandParameters, SqlConnectionOwnership.External);
            }

            /// <summary> 
            /// [调用者方式]执行指定数据库事务的数据阅读器,指定参数值. 
            /// </summary> 
            /// <remarks> 
            /// 此方法不提供访问存储过程输出参数和返回值参数. 
            /// 
            /// 示例:  
            ///  SqlDataReader dr = ExecuteReader(trans, "GetOrders", 24, 36); 
            /// </remarks> 
            /// <param name="transaction">一个有效的连接事务</param> 
            /// <param name="spName">存储过程名称</param> 
            /// <param name="parameterValues">分配给存储过程输入参数的对象数组</param> 
            /// <returns>返回包含结果集的SqlDataReader</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");

                // 如果有参数值 
                if ((parameterValues != null) && (parameterValues.Length > 0))
                {
                    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                    AssignParameterValues(commandParameters, parameterValues);

                    return ExecuteReader(transaction, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    // 没有参数值 
                    return ExecuteReader(transaction, CommandType.StoredProcedure, spName);
                }
            }

            #endregion ExecuteReader数据阅读器

            #region ExecuteScalar 返回结果集中的第一行第一列

            /// <summary> 
            /// 执行指定数据库连接字符串的命令,返回结果集中的第一行第一列. 
            /// </summary> 
            /// <remarks> 
            /// 示例:  
            ///  int orderCount = (int)ExecuteScalar(connString, CommandType.StoredProcedure, "GetOrderCount"); 
            /// </remarks> 
            /// <param name="connectionString">一个有效的数据库连接字符串</param> 
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
            /// <param name="commandText">存储过程名称或T-SQL语句</param> 
            /// <returns>返回结果集中的第一行第一列</returns> 
            public static object ExecuteScalar(string connectionString, CommandType commandType, string commandText)
            {
                // 执行参数为空的方法 
                return ExecuteScalar(connectionString, commandType, commandText, (SqlParameter[])null);
            }

            /// <summary> 
            /// 执行指定数据库连接字符串的命令,指定参数,返回结果集中的第一行第一列. 
            /// </summary> 
            /// <remarks> 
            /// 示例:  
            ///  int orderCount = (int)ExecuteScalar(connString, CommandType.StoredProcedure, "GetOrderCount", new SqlParameter("@prodid", 24)); 
            /// </remarks> 
            /// <param name="connectionString">一个有效的数据库连接字符串</param> 
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
            /// <param name="commandText">存储过程名称或T-SQL语句</param> 
            /// <param name="commandParameters">分配给命令的SqlParamter参数数组</param> 
            /// <returns>返回结果集中的第一行第一列</returns> 
            public static object ExecuteScalar(string connectionString, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
            {
                if (connectionString == null || connectionString.Length == 0) throw new ArgumentNullException("connectionString");
                // 创建并打开数据库连接对象,操作完成释放对象. 
                using (SqlConnection connection = new SqlConnection(connectionString))
                {
                    connection.Open();

                    // 调用指定数据库连接字符串重载方法. 
                    return ExecuteScalar(connection, commandType, commandText, commandParameters);
                }
            }

            /// <summary> 
            /// 执行指定数据库连接字符串的命令,指定参数值,返回结果集中的第一行第一列. 
            /// </summary> 
            /// <remarks> 
            /// 此方法不提供访问存储过程输出参数和返回值参数. 
            /// 
            /// 示例:  
            ///  int orderCount = (int)ExecuteScalar(connString, "GetOrderCount", 24, 36); 
            /// </remarks> 
            /// <param name="connectionString">一个有效的数据库连接字符串</param> 
            /// <param name="spName">存储过程名称</param> 
            /// <param name="parameterValues">分配给存储过程输入参数的对象数组</param> 
            /// <returns>返回结果集中的第一行第一列</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");

                // 如果有参数值 
                if ((parameterValues != null) && (parameterValues.Length > 0))
                {
                    // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
                    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                    // 给存储过程参数赋值 
                    AssignParameterValues(commandParameters, parameterValues);

                    // 调用重载方法 
                    return ExecuteScalar(connectionString, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    // 没有参数值 
                    return ExecuteScalar(connectionString, CommandType.StoredProcedure, spName);
                }
            }

            /// <summary> 
            /// 执行指定数据库连接对象的命令,返回结果集中的第一行第一列. 
            /// </summary> 
            /// <remarks> 
            /// 示例:  
            ///  int orderCount = (int)ExecuteScalar(conn, CommandType.StoredProcedure, "GetOrderCount"); 
            /// </remarks> 
            /// <param name="connection">一个有效的数据库连接对象</param> 
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
            /// <param name="commandText">存储过程名称或T-SQL语句</param> 
            /// <returns>返回结果集中的第一行第一列</returns> 
            public static object ExecuteScalar(SqlConnection connection, CommandType commandType, string commandText)
            {
                // 执行参数为空的方法 
                return ExecuteScalar(connection, commandType, commandText, (SqlParameter[])null);
            }

            /// <summary> 
            /// 执行指定数据库连接对象的命令,指定参数,返回结果集中的第一行第一列. 
            /// </summary> 
            /// <remarks> 
            /// 示例:  
            ///  int orderCount = (int)ExecuteScalar(conn, CommandType.StoredProcedure, "GetOrderCount", new SqlParameter("@prodid", 24)); 
            /// </remarks> 
            /// <param name="connection">一个有效的数据库连接对象</param> 
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
            /// <param name="commandText">存储过程名称或T-SQL语句</param> 
            /// <param name="commandParameters">分配给命令的SqlParamter参数数组</param> 
            /// <returns>返回结果集中的第一行第一列</returns> 
            public static object ExecuteScalar(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
            {
                if (connection == null) throw new ArgumentNullException("connection");

                // 创建SqlCommand命令,并进行预处理 
                SqlCommand cmd = new SqlCommand();

                bool mustCloseConnection = false;
                PrepareCommand(cmd, connection, (SqlTransaction)null, commandType, commandText, commandParameters, out mustCloseConnection);

                // 执行SqlCommand命令,并返回结果. 
                object retval = cmd.ExecuteScalar();

                // 清除参数,以便再次使用. 
                cmd.Parameters.Clear();

                if (mustCloseConnection)
                    connection.Close();

                return retval;
            }

            /// <summary> 
            /// 执行指定数据库连接对象的命令,指定参数值,返回结果集中的第一行第一列. 
            /// </summary> 
            /// <remarks> 
            /// 此方法不提供访问存储过程输出参数和返回值参数. 
            /// 
            /// 示例:  
            ///  int orderCount = (int)ExecuteScalar(conn, "GetOrderCount", 24, 36); 
            /// </remarks> 
            /// <param name="connection">一个有效的数据库连接对象</param> 
            /// <param name="spName">存储过程名称</param> 
            /// <param name="parameterValues">分配给存储过程输入参数的对象数组</param> 
            /// <returns>返回结果集中的第一行第一列</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");

                // 如果有参数值 
                if ((parameterValues != null) && (parameterValues.Length > 0))
                {
                    // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
                    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                    // 给存储过程参数赋值 
                    AssignParameterValues(commandParameters, parameterValues);

                    // 调用重载方法 
                    return ExecuteScalar(connection, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    // 没有参数值 
                    return ExecuteScalar(connection, CommandType.StoredProcedure, spName);
                }
            }

            /// <summary> 
            /// 执行指定数据库事务的命令,返回结果集中的第一行第一列. 
            /// </summary> 
            /// <remarks> 
            /// 示例:  
            ///  int orderCount = (int)ExecuteScalar(trans, CommandType.StoredProcedure, "GetOrderCount"); 
            /// </remarks> 
            /// <param name="transaction">一个有效的连接事务</param> 
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
            /// <param name="commandText">存储过程名称或T-SQL语句</param> 
            /// <returns>返回结果集中的第一行第一列</returns> 
            public static object ExecuteScalar(SqlTransaction transaction, CommandType commandType, string commandText)
            {
                // 执行参数为空的方法 
                return ExecuteScalar(transaction, commandType, commandText, (SqlParameter[])null);
            }

            /// <summary> 
            /// 执行指定数据库事务的命令,指定参数,返回结果集中的第一行第一列. 
            /// </summary> 
            /// <remarks> 
            /// 示例:  
            ///  int orderCount = (int)ExecuteScalar(trans, CommandType.StoredProcedure, "GetOrderCount", new SqlParameter("@prodid", 24)); 
            /// </remarks> 
            /// <param name="transaction">一个有效的连接事务</param> 
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
            /// <param name="commandText">存储过程名称或T-SQL语句</param> 
            /// <param name="commandParameters">分配给命令的SqlParamter参数数组</param> 
            /// <returns>返回结果集中的第一行第一列</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");

                // 创建SqlCommand命令,并进行预处理 
                SqlCommand cmd = new SqlCommand();
                bool mustCloseConnection = false;
                PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection);

                // 执行SqlCommand命令,并返回结果. 
                object retval = cmd.ExecuteScalar();

                // 清除参数,以便再次使用. 
                cmd.Parameters.Clear();
                return retval;
            }

            /// <summary> 
            /// 执行指定数据库事务的命令,指定参数值,返回结果集中的第一行第一列. 
            /// </summary> 
            /// <remarks> 
            /// 此方法不提供访问存储过程输出参数和返回值参数. 
            /// 
            /// 示例:  
            ///  int orderCount = (int)ExecuteScalar(trans, "GetOrderCount", 24, 36); 
            /// </remarks> 
            /// <param name="transaction">一个有效的连接事务</param> 
            /// <param name="spName">存储过程名称</param> 
            /// <param name="parameterValues">分配给存储过程输入参数的对象数组</param> 
            /// <returns>返回结果集中的第一行第一列</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");

                // 如果有参数值 
                if ((parameterValues != null) && (parameterValues.Length > 0))
                {
                    // PPull the parameters for this stored procedure from the parameter cache () 
                    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                    // 给存储过程参数赋值 
                    AssignParameterValues(commandParameters, parameterValues);

                    // 调用重载方法 
                    return ExecuteScalar(transaction, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    // 没有参数值 
                    return ExecuteScalar(transaction, CommandType.StoredProcedure, spName);
                }
            }

            #endregion ExecuteScalar

            #region ExecuteXmlReader XML阅读器
            /// <summary> 
            /// 执行指定数据库连接对象的SqlCommand命令,并产生一个XmlReader对象做为结果集返回. 
            /// </summary> 
            /// <remarks> 
            /// 示例:  
            ///  XmlReader r = ExecuteXmlReader(conn, CommandType.StoredProcedure, "GetOrders"); 
            /// </remarks> 
            /// <param name="connection">一个有效的数据库连接对象</param> 
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
            /// <param name="commandText">存储过程名称或T-SQL语句 using "FOR XML AUTO"</param> 
            /// <returns>返回XmlReader结果集对象.</returns> 
            public static XmlReader ExecuteXmlReader(SqlConnection connection, CommandType commandType, string commandText)
            {
                // 执行参数为空的方法 
                return ExecuteXmlReader(connection, commandType, commandText, (SqlParameter[])null);
            }

            /// <summary> 
            /// 执行指定数据库连接对象的SqlCommand命令,并产生一个XmlReader对象做为结果集返回,指定参数. 
            /// </summary> 
            /// <remarks> 
            /// 示例:  
            ///  XmlReader r = ExecuteXmlReader(conn, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24)); 
            /// </remarks> 
            /// <param name="connection">一个有效的数据库连接对象</param> 
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
            /// <param name="commandText">存储过程名称或T-SQL语句 using "FOR XML AUTO"</param> 
            /// <param name="commandParameters">分配给命令的SqlParamter参数数组</param> 
            /// <returns>返回XmlReader结果集对象.</returns> 
            public static XmlReader ExecuteXmlReader(SqlConnection connection, CommandType commandType, string commandText, params SqlParameter[] commandParameters)
            {
                if (connection == null) throw new ArgumentNullException("connection");

                bool mustCloseConnection = false;
                // 创建SqlCommand命令,并进行预处理 
                SqlCommand cmd = new SqlCommand();
                try
                {
                    PrepareCommand(cmd, connection, (SqlTransaction)null, commandType, commandText, commandParameters, out mustCloseConnection);

                    // 执行命令 
                    XmlReader retval = cmd.ExecuteXmlReader();

                    // 清除参数,以便再次使用. 
                    cmd.Parameters.Clear();

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

            /// <summary> 
            /// 执行指定数据库连接对象的SqlCommand命令,并产生一个XmlReader对象做为结果集返回,指定参数值. 
            /// </summary> 
            /// <remarks> 
            /// 此方法不提供访问存储过程输出参数和返回值参数. 
            /// 
            /// 示例:  
            ///  XmlReader r = ExecuteXmlReader(conn, "GetOrders", 24, 36); 
            /// </remarks> 
            /// <param name="connection">一个有效的数据库连接对象</param> 
            /// <param name="spName">存储过程名称 using "FOR XML AUTO"</param> 
            /// <param name="parameterValues">分配给存储过程输入参数的对象数组</param> 
            /// <returns>返回XmlReader结果集对象.</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");

                // 如果有参数值 
                if ((parameterValues != null) && (parameterValues.Length > 0))
                {
                    // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
                    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                    // 给存储过程参数赋值 
                    AssignParameterValues(commandParameters, parameterValues);

                    // 调用重载方法 
                    return ExecuteXmlReader(connection, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    // 没有参数值 
                    return ExecuteXmlReader(connection, CommandType.StoredProcedure, spName);
                }
            }

            /// <summary> 
            /// 执行指定数据库事务的SqlCommand命令,并产生一个XmlReader对象做为结果集返回. 
            /// </summary> 
            /// <remarks> 
            /// 示例:  
            ///  XmlReader r = ExecuteXmlReader(trans, CommandType.StoredProcedure, "GetOrders"); 
            /// </remarks> 
            /// <param name="transaction">一个有效的连接事务</param> 
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
            /// <param name="commandText">存储过程名称或T-SQL语句 using "FOR XML AUTO"</param> 
            /// <returns>返回XmlReader结果集对象.</returns> 
            public static XmlReader ExecuteXmlReader(SqlTransaction transaction, CommandType commandType, string commandText)
            {
                // 执行参数为空的方法 
                return ExecuteXmlReader(transaction, commandType, commandText, (SqlParameter[])null);
            }

            /// <summary> 
            /// 执行指定数据库事务的SqlCommand命令,并产生一个XmlReader对象做为结果集返回,指定参数. 
            /// </summary> 
            /// <remarks> 
            /// 示例:  
            ///  XmlReader r = ExecuteXmlReader(trans, CommandType.StoredProcedure, "GetOrders", new SqlParameter("@prodid", 24)); 
            /// </remarks> 
            /// <param name="transaction">一个有效的连接事务</param> 
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
            /// <param name="commandText">存储过程名称或T-SQL语句 using "FOR XML AUTO"</param> 
            /// <param name="commandParameters">分配给命令的SqlParamter参数数组</param> 
            /// <returns>返回XmlReader结果集对象.</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");

                // 创建SqlCommand命令,并进行预处理 
                SqlCommand cmd = new SqlCommand();
                bool mustCloseConnection = false;
                PrepareCommand(cmd, transaction.Connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection);

                // 执行命令 
                XmlReader retval = cmd.ExecuteXmlReader();

                // 清除参数,以便再次使用. 
                cmd.Parameters.Clear();
                return retval;
            }

            /// <summary> 
            /// 执行指定数据库事务的SqlCommand命令,并产生一个XmlReader对象做为结果集返回,指定参数值. 
            /// </summary> 
            /// <remarks> 
            /// 此方法不提供访问存储过程输出参数和返回值参数. 
            /// 
            /// 示例:  
            ///  XmlReader r = ExecuteXmlReader(trans, "GetOrders", 24, 36); 
            /// </remarks> 
            /// <param name="transaction">一个有效的连接事务</param> 
            /// <param name="spName">存储过程名称</param> 
            /// <param name="parameterValues">分配给存储过程输入参数的对象数组</param> 
            /// <returns>返回一个包含结果集的DataSet.</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");

                // 如果有参数值 
                if ((parameterValues != null) && (parameterValues.Length > 0))
                {
                    // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
                    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                    // 给存储过程参数赋值 
                    AssignParameterValues(commandParameters, parameterValues);

                    // 调用重载方法 
                    return ExecuteXmlReader(transaction, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    // 没有参数值 
                    return ExecuteXmlReader(transaction, CommandType.StoredProcedure, spName);
                }
            }

            #endregion ExecuteXmlReader 阅读器结束

            #region FillDataset 填充数据集
            /// <summary> 
            /// 执行指定数据库连接字符串的命令,映射数据表并填充数据集. 
            /// </summary> 
            /// <remarks> 
            /// 示例:  
            ///  FillDataset(connString, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}); 
            /// </remarks> 
            /// <param name="connectionString">一个有效的数据库连接字符串</param> 
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
            /// <param name="commandText">存储过程名称或T-SQL语句</param> 
            /// <param name="dataSet">要填充结果集的DataSet实例</param> 
            /// <param name="tableNames">表映射的数据表数组 
            /// 用户定义的表名 (可有是实际的表名.)</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");

                // 创建并打开数据库连接对象,操作完成释放对象. 
                using (SqlConnection connection = new SqlConnection(connectionString))
                {
                    connection.Open();

                    // 调用指定数据库连接字符串重载方法. 
                    FillDataset(connection, commandType, commandText, dataSet, tableNames);
                }
            }

            /// <summary> 
            /// 执行指定数据库连接字符串的命令,映射数据表并填充数据集.指定命令参数. 
            /// </summary> 
            /// <remarks> 
            /// 示例:  
            ///  FillDataset(connString, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}, new SqlParameter("@prodid", 24)); 
            /// </remarks> 
            /// <param name="connectionString">一个有效的数据库连接字符串</param> 
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
            /// <param name="commandText">存储过程名称或T-SQL语句</param> 
            /// <param name="commandParameters">分配给命令的SqlParamter参数数组</param> 
            /// <param name="dataSet">要填充结果集的DataSet实例</param> 
            /// <param name="tableNames">表映射的数据表数组 
            /// 用户定义的表名 (可有是实际的表名.) 
            /// </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");
                // 创建并打开数据库连接对象,操作完成释放对象. 
                using (SqlConnection connection = new SqlConnection(connectionString))
                {
                    connection.Open();

                    // 调用指定数据库连接字符串重载方法. 
                    FillDataset(connection, commandType, commandText, dataSet, tableNames, commandParameters);
                }
            }

            /// <summary> 
            /// 执行指定数据库连接字符串的命令,映射数据表并填充数据集,指定存储过程参数值. 
            /// </summary> 
            /// <remarks> 
            /// 此方法不提供访问存储过程输出参数和返回值参数. 
            /// 
            /// 示例:  
            ///  FillDataset(connString, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}, 24); 
            /// </remarks> 
            /// <param name="connectionString">一个有效的数据库连接字符串</param> 
            /// <param name="spName">存储过程名称</param> 
            /// <param name="dataSet">要填充结果集的DataSet实例</param> 
            /// <param name="tableNames">表映射的数据表数组 
            /// 用户定义的表名 (可有是实际的表名.) 
            /// </param>    
            /// <param name="parameterValues">分配给存储过程输入参数的对象数组</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");
                // 创建并打开数据库连接对象,操作完成释放对象. 
                using (SqlConnection connection = new SqlConnection(connectionString))
                {
                    connection.Open();

                    // 调用指定数据库连接字符串重载方法. 
                    FillDataset(connection, spName, dataSet, tableNames, parameterValues);
                }
            }

            /// <summary> 
            /// 执行指定数据库连接对象的命令,映射数据表并填充数据集. 
            /// </summary> 
            /// <remarks> 
            /// 示例:  
            ///  FillDataset(conn, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}); 
            /// </remarks> 
            /// <param name="connection">一个有效的数据库连接对象</param> 
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
            /// <param name="commandText">存储过程名称或T-SQL语句</param> 
            /// <param name="dataSet">要填充结果集的DataSet实例</param> 
            /// <param name="tableNames">表映射的数据表数组 
            /// 用户定义的表名 (可有是实际的表名.) 
            /// </param>    
            public static void FillDataset(SqlConnection connection, CommandType commandType,
                string commandText, DataSet dataSet, string[] tableNames)
            {
                FillDataset(connection, commandType, commandText, dataSet, tableNames, null);
            }

            /// <summary> 
            /// 执行指定数据库连接对象的命令,映射数据表并填充数据集,指定参数. 
            /// </summary> 
            /// <remarks> 
            /// 示例:  
            ///  FillDataset(conn, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}, new SqlParameter("@prodid", 24)); 
            /// </remarks> 
            /// <param name="connection">一个有效的数据库连接对象</param> 
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
            /// <param name="commandText">存储过程名称或T-SQL语句</param> 
            /// <param name="dataSet">要填充结果集的DataSet实例</param> 
            /// <param name="tableNames">表映射的数据表数组 
            /// 用户定义的表名 (可有是实际的表名.) 
            /// </param> 
            /// <param name="commandParameters">分配给命令的SqlParamter参数数组</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> 
            /// 执行指定数据库连接对象的命令,映射数据表并填充数据集,指定存储过程参数值. 
            /// </summary> 
            /// <remarks> 
            /// 此方法不提供访问存储过程输出参数和返回值参数. 
            /// 
            /// 示例:  
            ///  FillDataset(conn, "GetOrders", ds, new string[] {"orders"}, 24, 36); 
            /// </remarks> 
            /// <param name="connection">一个有效的数据库连接对象</param> 
            /// <param name="spName">存储过程名称</param> 
            /// <param name="dataSet">要填充结果集的DataSet实例</param> 
            /// <param name="tableNames">表映射的数据表数组 
            /// 用户定义的表名 (可有是实际的表名.) 
            /// </param> 
            /// <param name="parameterValues">分配给存储过程输入参数的对象数组</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");

                // 如果有参数值 
                if ((parameterValues != null) && (parameterValues.Length > 0))
                {
                    // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
                    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                    // 给存储过程参数赋值 
                    AssignParameterValues(commandParameters, parameterValues);

                    // 调用重载方法 
                    FillDataset(connection, CommandType.StoredProcedure, spName, dataSet, tableNames, commandParameters);
                }
                else
                {
                    // 没有参数值 
                    FillDataset(connection, CommandType.StoredProcedure, spName, dataSet, tableNames);
                }
            }

            /// <summary> 
            /// 执行指定数据库事务的命令,映射数据表并填充数据集. 
            /// </summary> 
            /// <remarks> 
            /// 示例:  
            ///  FillDataset(trans, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}); 
            /// </remarks> 
            /// <param name="transaction">一个有效的连接事务</param> 
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
            /// <param name="commandText">存储过程名称或T-SQL语句</param> 
            /// <param name="dataSet">要填充结果集的DataSet实例</param> 
            /// <param name="tableNames">表映射的数据表数组 
            /// 用户定义的表名 (可有是实际的表名.) 
            /// </param> 
            public static void FillDataset(SqlTransaction transaction, CommandType commandType,
                string commandText,
                DataSet dataSet, string[] tableNames)
            {
                FillDataset(transaction, commandType, commandText, dataSet, tableNames, null);
            }

            /// <summary> 
            /// 执行指定数据库事务的命令,映射数据表并填充数据集,指定参数. 
            /// </summary> 
            /// <remarks> 
            /// 示例:  
            ///  FillDataset(trans, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}, new SqlParameter("@prodid", 24)); 
            /// </remarks> 
            /// <param name="transaction">一个有效的连接事务</param> 
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
            /// <param name="commandText">存储过程名称或T-SQL语句</param> 
            /// <param name="dataSet">要填充结果集的DataSet实例</param> 
            /// <param name="tableNames">表映射的数据表数组 
            /// 用户定义的表名 (可有是实际的表名.) 
            /// </param> 
            /// <param name="commandParameters">分配给命令的SqlParamter参数数组</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> 
            /// 执行指定数据库事务的命令,映射数据表并填充数据集,指定存储过程参数值. 
            /// </summary> 
            /// <remarks> 
            /// 此方法不提供访问存储过程输出参数和返回值参数. 
            /// 
            /// 示例:  
            ///  FillDataset(trans, "GetOrders", ds, new string[]{"orders"}, 24, 36); 
            /// </remarks> 
            /// <param name="transaction">一个有效的连接事务</param> 
            /// <param name="spName">存储过程名称</param> 
            /// <param name="dataSet">要填充结果集的DataSet实例</param> 
            /// <param name="tableNames">表映射的数据表数组 
            /// 用户定义的表名 (可有是实际的表名.) 
            /// </param> 
            /// <param name="parameterValues">分配给存储过程输入参数的对象数组</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");

                // 如果有参数值 
                if ((parameterValues != null) && (parameterValues.Length > 0))
                {
                    // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
                    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                    // 给存储过程参数赋值 
                    AssignParameterValues(commandParameters, parameterValues);

                    // 调用重载方法 
                    FillDataset(transaction, CommandType.StoredProcedure, spName, dataSet, tableNames, commandParameters);
                }
                else
                {
                    // 没有参数值 
                    FillDataset(transaction, CommandType.StoredProcedure, spName, dataSet, tableNames);
                }
            }

            /// <summary> 
            /// [私有方法][内部调用]执行指定数据库连接对象/事务的命令,映射数据表并填充数据集,DataSet/TableNames/SqlParameters. 
            /// </summary> 
            /// <remarks> 
            /// 示例:  
            ///  FillDataset(conn, trans, CommandType.StoredProcedure, "GetOrders", ds, new string[] {"orders"}, new SqlParameter("@prodid", 24)); 
            /// </remarks> 
            /// <param name="connection">一个有效的数据库连接对象</param> 
            /// <param name="transaction">一个有效的连接事务</param> 
            /// <param name="commandType">命令类型 (存储过程,命令文本或其它)</param> 
            /// <param name="commandText">存储过程名称或T-SQL语句</param> 
            /// <param name="dataSet">要填充结果集的DataSet实例</param> 
            /// <param name="tableNames">表映射的数据表数组 
            /// 用户定义的表名 (可有是实际的表名.) 
            /// </param> 
            /// <param name="commandParameters">分配给命令的SqlParamter参数数组</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");

                // 创建SqlCommand命令,并进行预处理 
                SqlCommand command = new SqlCommand();
                bool mustCloseConnection = false;
                PrepareCommand(command, connection, transaction, commandType, commandText, commandParameters, out mustCloseConnection);

                // 执行命令 
                using (SqlDataAdapter dataAdapter = new SqlDataAdapter(command))
                {

                    // 追加表映射 
                    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();
                        }
                    }

                    // 填充数据集使用默认表名称 
                    dataAdapter.Fill(dataSet);

                    // 清除参数,以便再次使用. 
                    command.Parameters.Clear();
                }

                if (mustCloseConnection)
                    connection.Close();
            }
            #endregion

            #region UpdateDataset 更新数据集
            /// <summary> 
            /// 执行数据集更新到数据库,指定inserted, updated, or deleted命令. 
            /// </summary> 
            /// <remarks> 
            /// 示例:  
            ///  UpdateDataset(conn, insertCommand, deleteCommand, updateCommand, dataSet, "Order"); 
            /// </remarks> 
            /// <param name="insertCommand">[追加记录]一个有效的T-SQL语句或存储过程</param> 
            /// <param name="deleteCommand">[删除记录]一个有效的T-SQL语句或存储过程</param> 
            /// <param name="updateCommand">[更新记录]一个有效的T-SQL语句或存储过程</param> 
            /// <param name="dataSet">要更新到数据库的DataSet</param> 
            /// <param name="tableName">要更新到数据库的DataTable</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");

                // 创建SqlDataAdapter,当操作完成后释放. 
                using (SqlDataAdapter dataAdapter = new SqlDataAdapter())
                {
                    // 设置数据适配器命令 
                    dataAdapter.UpdateCommand = updateCommand;
                    dataAdapter.InsertCommand = insertCommand;
                    dataAdapter.DeleteCommand = deleteCommand;

                    // 更新数据集改变到数据库 
                    dataAdapter.Update(dataSet, tableName);

                    // 提交所有改变到数据集. 
                    dataSet.AcceptChanges();
                }
            }
            #endregion

            #region CreateCommand 创建一条SqlCommand命令
            /// <summary> 
            /// 创建SqlCommand命令,指定数据库连接对象,存储过程名和参数. 
            /// </summary> 
            /// <remarks> 
            /// 示例:  
            ///  SqlCommand command = CreateCommand(conn, "AddCustomer", "CustomerID", "CustomerName"); 
            /// </remarks> 
            /// <param name="connection">一个有效的数据库连接对象</param> 
            /// <param name="spName">存储过程名称</param> 
            /// <param name="sourceColumns">源表的列名称数组</param> 
            /// <returns>返回SqlCommand命令</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");

                // 创建命令 
                SqlCommand cmd = new SqlCommand(spName, connection);
                cmd.CommandType = CommandType.StoredProcedure;

                // 如果有参数值 
                if ((sourceColumns != null) && (sourceColumns.Length > 0))
                {
                    // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
                    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                    // 将源表的列到映射到DataSet命令中. 
                    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 类型化参数(DataRow)
            /// <summary> 
            /// 执行指定连接数据库连接字符串的存储过程,使用DataRow做为参数值,返回受影响的行数. 
            /// </summary> 
            /// <param name="connectionString">一个有效的数据库连接字符串</param> 
            /// <param name="spName">存储过程名称</param> 
            /// <param name="dataRow">使用DataRow作为参数值</param> 
            /// <returns>返回影响的行数</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");

                // 如果row有值,存储过程必须初始化. 
                if (dataRow != null && dataRow.ItemArray.Length > 0)
                {
                    // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
                    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                    // 分配参数值 
                    AssignParameterValues(commandParameters, dataRow);

                    return SqlHelper.ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    return SqlHelper.ExecuteNonQuery(connectionString, CommandType.StoredProcedure, spName);
                }
            }

            /// <summary> 
            /// 执行指定连接数据库连接对象的存储过程,使用DataRow做为参数值,返回受影响的行数. 
            /// </summary> 
            /// <param name="connection">一个有效的数据库连接对象</param> 
            /// <param name="spName">存储过程名称</param> 
            /// <param name="dataRow">使用DataRow作为参数值</param> 
            /// <returns>返回影响的行数</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");

                // 如果row有值,存储过程必须初始化. 
                if (dataRow != null && dataRow.ItemArray.Length > 0)
                {
                    // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
                    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                    // 分配参数值 
                    AssignParameterValues(commandParameters, dataRow);

                    return SqlHelper.ExecuteNonQuery(connection, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    return SqlHelper.ExecuteNonQuery(connection, CommandType.StoredProcedure, spName);
                }
            }

            /// <summary> 
            /// 执行指定连接数据库事物的存储过程,使用DataRow做为参数值,返回受影响的行数. 
            /// </summary> 
            /// <param name="transaction">一个有效的连接事务 object</param> 
            /// <param name="spName">存储过程名称</param> 
            /// <param name="dataRow">使用DataRow作为参数值</param> 
            /// <returns>返回影响的行数</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)
                {
                    // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
                    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                    // 分配参数值 
                    AssignParameterValues(commandParameters, dataRow);

                    return SqlHelper.ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    return SqlHelper.ExecuteNonQuery(transaction, CommandType.StoredProcedure, spName);
                }
            }
            #endregion

            #region ExecuteDatasetTypedParams 类型化参数(DataRow)
            /// <summary> 
            /// 执行指定连接数据库连接字符串的存储过程,使用DataRow做为参数值,返回DataSet. 
            /// </summary> 
            /// <param name="connectionString">一个有效的数据库连接字符串</param> 
            /// <param name="spName">存储过程名称</param> 
            /// <param name="dataRow">使用DataRow作为参数值</param> 
            /// <returns>返回一个包含结果集的DataSet.</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");

                //如果row有值,存储过程必须初始化. 
                if (dataRow != null && dataRow.ItemArray.Length > 0)
                {
                    // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
                    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                    // 分配参数值 
                    AssignParameterValues(commandParameters, dataRow);

                    return SqlHelper.ExecuteDataset(connectionString, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    return SqlHelper.ExecuteDataset(connectionString, CommandType.StoredProcedure, spName);
                }
            }

            /// <summary> 
            /// 执行指定连接数据库连接对象的存储过程,使用DataRow做为参数值,返回DataSet. 
            /// </summary> 
            /// <param name="connection">一个有效的数据库连接对象</param> 
            /// <param name="spName">存储过程名称</param> 
            /// <param name="dataRow">使用DataRow作为参数值</param> 
            /// <returns>返回一个包含结果集的DataSet.</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");

                // 如果row有值,存储过程必须初始化. 
                if (dataRow != null && dataRow.ItemArray.Length > 0)
                {
                    // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
                    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                    // 分配参数值 
                    AssignParameterValues(commandParameters, dataRow);

                    return SqlHelper.ExecuteDataset(connection, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    return SqlHelper.ExecuteDataset(connection, CommandType.StoredProcedure, spName);
                }
            }

            /// <summary> 
            /// 执行指定连接数据库事务的存储过程,使用DataRow做为参数值,返回DataSet. 
            /// </summary> 
            /// <param name="transaction">一个有效的连接事务 object</param> 
            /// <param name="spName">存储过程名称</param> 
            /// <param name="dataRow">使用DataRow作为参数值</param> 
            /// <returns>返回一个包含结果集的DataSet.</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");

                // 如果row有值,存储过程必须初始化. 
                if (dataRow != null && dataRow.ItemArray.Length > 0)
                {
                    // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
                    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                    // 分配参数值 
                    AssignParameterValues(commandParameters, dataRow);

                    return SqlHelper.ExecuteDataset(transaction, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    return SqlHelper.ExecuteDataset(transaction, CommandType.StoredProcedure, spName);
                }
            }

            #endregion

            #region ExecuteReaderTypedParams 类型化参数(DataRow)
            /// <summary> 
            /// 执行指定连接数据库连接字符串的存储过程,使用DataRow做为参数值,返回DataReader. 
            /// </summary> 
            /// <param name="connectionString">一个有效的数据库连接字符串</param> 
            /// <param name="spName">存储过程名称</param> 
            /// <param name="dataRow">使用DataRow作为参数值</param> 
            /// <returns>返回包含结果集的SqlDataReader</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");

                // 如果row有值,存储过程必须初始化. 
                if (dataRow != null && dataRow.ItemArray.Length > 0)
                {
                    // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
                    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                    // 分配参数值 
                    AssignParameterValues(commandParameters, dataRow);

                    return SqlHelper.ExecuteReader(connectionString, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    return SqlHelper.ExecuteReader(connectionString, CommandType.StoredProcedure, spName);
                }
            }


            /// <summary> 
            /// 执行指定连接数据库连接对象的存储过程,使用DataRow做为参数值,返回DataReader. 
            /// </summary> 
            /// <param name="connection">一个有效的数据库连接对象</param> 
            /// <param name="spName">存储过程名称</param> 
            /// <param name="dataRow">使用DataRow作为参数值</param> 
            /// <returns>返回包含结果集的SqlDataReader</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");

                // 如果row有值,存储过程必须初始化. 
                if (dataRow != null && dataRow.ItemArray.Length > 0)
                {
                    // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
                    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                    // 分配参数值 
                    AssignParameterValues(commandParameters, dataRow);

                    return SqlHelper.ExecuteReader(connection, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    return SqlHelper.ExecuteReader(connection, CommandType.StoredProcedure, spName);
                }
            }

            /// <summary> 
            /// 执行指定连接数据库事物的存储过程,使用DataRow做为参数值,返回DataReader. 
            /// </summary> 
            /// <param name="transaction">一个有效的连接事务 object</param> 
            /// <param name="spName">存储过程名称</param> 
            /// <param name="dataRow">使用DataRow作为参数值</param> 
            /// <returns>返回包含结果集的SqlDataReader</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");

                // 如果row有值,存储过程必须初始化. 
                if (dataRow != null && dataRow.ItemArray.Length > 0)
                {
                    // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
                    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                    // 分配参数值 
                    AssignParameterValues(commandParameters, dataRow);

                    return SqlHelper.ExecuteReader(transaction, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    return SqlHelper.ExecuteReader(transaction, CommandType.StoredProcedure, spName);
                }
            }
            #endregion

            #region ExecuteScalarTypedParams 类型化参数(DataRow)
            /// <summary> 
            /// 执行指定连接数据库连接字符串的存储过程,使用DataRow做为参数值,返回结果集中的第一行第一列. 
            /// </summary> 
            /// <param name="connectionString">一个有效的数据库连接字符串</param> 
            /// <param name="spName">存储过程名称</param> 
            /// <param name="dataRow">使用DataRow作为参数值</param> 
            /// <returns>返回结果集中的第一行第一列</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");

                // 如果row有值,存储过程必须初始化. 
                if (dataRow != null && dataRow.ItemArray.Length > 0)
                {
                    // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
                    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connectionString, spName);

                    // 分配参数值 
                    AssignParameterValues(commandParameters, dataRow);

                    return SqlHelper.ExecuteScalar(connectionString, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    return SqlHelper.ExecuteScalar(connectionString, CommandType.StoredProcedure, spName);
                }
            }

            /// <summary> 
            /// 执行指定连接数据库连接对象的存储过程,使用DataRow做为参数值,返回结果集中的第一行第一列. 
            /// </summary> 
            /// <param name="connection">一个有效的数据库连接对象</param> 
            /// <param name="spName">存储过程名称</param> 
            /// <param name="dataRow">使用DataRow作为参数值</param> 
            /// <returns>返回结果集中的第一行第一列</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");

                // 如果row有值,存储过程必须初始化. 
                if (dataRow != null && dataRow.ItemArray.Length > 0)
                {
                    // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
                    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                    // 分配参数值 
                    AssignParameterValues(commandParameters, dataRow);

                    return SqlHelper.ExecuteScalar(connection, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    return SqlHelper.ExecuteScalar(connection, CommandType.StoredProcedure, spName);
                }
            }

            /// <summary> 
            /// 执行指定连接数据库事务的存储过程,使用DataRow做为参数值,返回结果集中的第一行第一列. 
            /// </summary> 
            /// <param name="transaction">一个有效的连接事务 object</param> 
            /// <param name="spName">存储过程名称</param> 
            /// <param name="dataRow">使用DataRow作为参数值</param> 
            /// <returns>返回结果集中的第一行第一列</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");

                // 如果row有值,存储过程必须初始化. 
                if (dataRow != null && dataRow.ItemArray.Length > 0)
                {
                    // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
                    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                    // 分配参数值 
                    AssignParameterValues(commandParameters, dataRow);

                    return SqlHelper.ExecuteScalar(transaction, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    return SqlHelper.ExecuteScalar(transaction, CommandType.StoredProcedure, spName);
                }
            }
            #endregion

            #region ExecuteXmlReaderTypedParams 类型化参数(DataRow)
            /// <summary> 
            /// 执行指定连接数据库连接对象的存储过程,使用DataRow做为参数值,返回XmlReader类型的结果集. 
            /// </summary> 
            /// <param name="connection">一个有效的数据库连接对象</param> 
            /// <param name="spName">存储过程名称</param> 
            /// <param name="dataRow">使用DataRow作为参数值</param> 
            /// <returns>返回XmlReader结果集对象.</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");

                // 如果row有值,存储过程必须初始化. 
                if (dataRow != null && dataRow.ItemArray.Length > 0)
                {
                    // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
                    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(connection, spName);

                    // 分配参数值 
                    AssignParameterValues(commandParameters, dataRow);

                    return SqlHelper.ExecuteXmlReader(connection, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    return SqlHelper.ExecuteXmlReader(connection, CommandType.StoredProcedure, spName);
                }
            }

            /// <summary> 
            /// 执行指定连接数据库事务的存储过程,使用DataRow做为参数值,返回XmlReader类型的结果集. 
            /// </summary> 
            /// <param name="transaction">一个有效的连接事务 object</param> 
            /// <param name="spName">存储过程名称</param> 
            /// <param name="dataRow">使用DataRow作为参数值</param> 
            /// <returns>返回XmlReader结果集对象.</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");

                // 如果row有值,存储过程必须初始化. 
                if (dataRow != null && dataRow.ItemArray.Length > 0)
                {
                    // 从缓存中加载存储过程参数,如果缓存中不存在则从数据库中检索参数信息并加载到缓存中. () 
                    SqlParameter[] commandParameters = SqlHelperParameterCache.GetSpParameterSet(transaction.Connection, spName);

                    // 分配参数值 
                    AssignParameterValues(commandParameters, dataRow);

                    return SqlHelper.ExecuteXmlReader(transaction, CommandType.StoredProcedure, spName, commandParameters);
                }
                else
                {
                    return SqlHelper.ExecuteXmlReader(transaction, CommandType.StoredProcedure, spName);
                }
            }
            #endregion

        }

        /// <summary> 
        /// SqlHelperParameterCache提供缓存存储过程参数,并能够在运行时从存储过程中探索参数. 
        /// </summary> 
        public sealed class SqlHelperParameterCache
        {
            #region 私有方法,字段,构造函数
            // 私有构造函数,妨止类被实例化. 
            private SqlHelperParameterCache() { }

            // 这个方法要注意 
            private static Hashtable paramCache = Hashtable.Synchronized(new Hashtable());

            /// <summary> 
            /// 探索运行时的存储过程,返回SqlParameter参数数组. 
            /// 初始化参数值为 DBNull.Value. 
            /// </summary> 
            /// <param name="connection">一个有效的数据库连接</param> 
            /// <param name="spName">存储过程名称</param> 
            /// <param name="includeReturnValueParameter">是否包含返回值参数</param> 
            /// <returns>返回SqlParameter参数数组</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();
                // 检索cmd指定的存储过程的参数信息,并填充到cmd的Parameters参数集中. 
                SqlCommandBuilder.DeriveParameters(cmd);
                connection.Close();
                // 如果不包含返回值参数,将参数集中的每一个参数删除. 
                if (!includeReturnValueParameter)
                {
                    cmd.Parameters.RemoveAt(0);
                }

                // 创建参数数组 
                SqlParameter[] discoveredParameters = new SqlParameter[cmd.Parameters.Count];
                // 将cmd的Parameters参数集复制到discoveredParameters数组. 
                cmd.Parameters.CopyTo(discoveredParameters, 0);

                // 初始化参数值为 DBNull.Value. 
                foreach (SqlParameter discoveredParameter in discoveredParameters)
                {
                    discoveredParameter.Value = DBNull.Value;
                }
                return discoveredParameters;
            }

            /// <summary> 
            /// SqlParameter参数数组的深层拷贝. 
            /// </summary> 
            /// <param name="originalParameters">原始参数数组</param> 
            /// <returns>返回一个同样的参数数组</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 私有方法,字段,构造函数结束

            #region 缓存方法

            /// <summary> 
            /// 追加参数数组到缓存. 
            /// </summary> 
            /// <param name="connectionString">一个有效的数据库连接字符串</param> 
            /// <param name="commandText">存储过程名或SQL语句</param> 
            /// <param name="commandParameters">要缓存的参数数组</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> 
            /// 从缓存中获取参数数组. 
            /// </summary> 
            /// <param name="connectionString">一个有效的数据库连接字符</param> 
            /// <param name="commandText">存储过程名或SQL语句</param> 
            /// <returns>参数数组</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 缓存方法结束

            #region 检索指定的存储过程的参数集

            /// <summary> 
            /// 返回指定的存储过程的参数集 
            /// </summary> 
            /// <remarks> 
            /// 这个方法将查询数据库,并将信息存储到缓存. 
            /// </remarks> 
            /// <param name="connectionString">一个有效的数据库连接字符</param> 
            /// <param name="spName">存储过程名</param> 
            /// <returns>返回SqlParameter参数数组</returns> 
            public static SqlParameter[] GetSpParameterSet(string connectionString, string spName)
            {
                return GetSpParameterSet(connectionString, spName, false);
            }

            /// <summary> 
            /// 返回指定的存储过程的参数集 
            /// </summary> 
            /// <remarks> 
            /// 这个方法将查询数据库,并将信息存储到缓存. 
            /// </remarks> 
            /// <param name="connectionString">一个有效的数据库连接字符.</param> 
            /// <param name="spName">存储过程名</param> 
            /// <param name="includeReturnValueParameter">是否包含返回值参数</param> 
            /// <returns>返回SqlParameter参数数组</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> 
            /// [内部]返回指定的存储过程的参数集(使用连接对象). 
            /// </summary> 
            /// <remarks> 
            /// 这个方法将查询数据库,并将信息存储到缓存. 
            /// </remarks> 
            /// <param name="connection">一个有效的数据库连接字符</param> 
            /// <param name="spName">存储过程名</param> 
            /// <returns>返回SqlParameter参数数组</returns> 
            internal static SqlParameter[] GetSpParameterSet(SqlConnection connection, string spName)
            {
                return GetSpParameterSet(connection, spName, false);
            }

            /// <summary> 
            /// [内部]返回指定的存储过程的参数集(使用连接对象) 
            /// </summary> 
            /// <remarks> 
            /// 这个方法将查询数据库,并将信息存储到缓存. 
            /// </remarks> 
            /// <param name="connection">一个有效的数据库连接对象</param> 
            /// <param name="spName">存储过程名</param> 
            /// <param name="includeReturnValueParameter"> 
            /// 是否包含返回值参数 
            /// </param> 
            /// <returns>返回SqlParameter参数数组</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> 
            /// [私有]返回指定的存储过程的参数集(使用连接对象) 
            /// </summary> 
            /// <param name="connection">一个有效的数据库连接对象</param> 
            /// <param name="spName">存储过程名</param> 
            /// <param name="includeReturnValueParameter">是否包含返回值参数</param> 
            /// <returns>返回SqlParameter参数数组</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);
            }

            #endregion 参数集检索结束

        } 

    }