sqlhelper

using System;  
using System.Collections.Generic;  
using System.Linq;  
using System.Text;  
using System.Data.SqlClient;    
using System.Collections;  
using System.Data;  
using System.Configuration;  
using System.Web;  
 
 
public sealed class SqlHelper  
{  
 
    public static string connectionString = ConfigurationManager.ConnectionStrings["db_JXCconn"].ConnectionString;  
 
    public SqlHelper()  
    {  
    } 
 
    #region 公用方法  
    public static int GetMaxID(string FieldName, string TableName)  
    {  
        string strsql = "select max(" + FieldName + ")+1 from " + TableName;  
        object obj = SqlHelper.GetSingle(strsql);  
        if (obj == null)  
        {  
            return 1;  
        }  
        else 
        {  
            return int.Parse(obj.ToString());  
        }  
    }  
 
    public static bool Exists(string strSql)  
    {  
        object obj = SqlHelper.GetSingle(strSql);  
        int cmdresult;  
        if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))  
        {  
            cmdresult = 0;  
        }  
        else 
        {  
            cmdresult = int.Parse(obj.ToString());  
        }  
        if (cmdresult == 0)  
        {  
            return false;  
        }  
        else 
        {  
            return true;  
        }  
    }  
 
    public static bool Exists(string strSql, params SqlParameter[] cmdParms)  
    {  
        object obj = SqlHelper.GetSingle(strSql, cmdParms);  
        int cmdresult;  
        if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))  
        {  
            cmdresult = 0;  
        }  
        else 
        {  
            cmdresult = int.Parse(obj.ToString());  
        }  
        if (cmdresult == 0)  
        {  
            return false;  
        }  
        else 
        {  
            return true;  
        }  
    } 
    #endregion 
 
    #region  执行简单SQL语句  
    /// <summary>  
    /// 执行SQL语句，返回影响的记录数  
    /// </summary>  
    /// <param name="SQLString">SQL语句</param>  
    /// <returns>影响的记录数</returns>  
    public static int ExecuteSql(string SQLString)  
    {  
        using (SqlConnection connection = new SqlConnection(connectionString))  
        {  
            using (SqlCommand cmd = new SqlCommand(SQLString, connection))  
            {  
                try 
                {  
                    connection.Open();  
                    int rows = cmd.ExecuteNonQuery();  
                    return rows;  
                }  
                catch (System.Data.SqlClient.SqlException E)  
                {  
                    connection.Close();  
                    throw new Exception(E.Message);  
                }  
            }  
        }  
    }  
 
    /// <summary>  
    /// 执行SQL语句，返回影响的记录数 适用于select语句  
    /// </summary>  
    /// <param name="SQLString">SQL语句</param>  
    /// <returns>影响的记录数</returns>  
    public static int ExecuteSql2(string SQLString)  
    {  
        using (SqlConnection connection = new SqlConnection(connectionString))  
        {  
            using (SqlCommand cmd = new SqlCommand(SQLString, connection))  
            {  
                try 
                {  
                    connection.Open();  
                    int rows = Convert.ToInt32(cmd.ExecuteScalar());  
                    return rows;  
                }  
                catch (System.Data.SqlClient.SqlException E)  
                {  
                    connection.Close();  
                    throw new Exception(E.Message);  
                }  
            }  
        }  
    }  
 
    /// <summary>  
    /// 执行多条SQL语句，实现数据库事务。  
    /// </summary>  
    /// <param name="SQLStringList">多条SQL语句</param>       
    public static void ExecuteSqlTran(ArrayList SQLStringList)  
    {  
        using (SqlConnection conn = new SqlConnection(connectionString))  
        {  
            conn.Open();  
            SqlCommand cmd = new SqlCommand();  
            cmd.Connection = conn;  
            SqlTransaction tx = conn.BeginTransaction();  
            cmd.Transaction = tx;  
            try 
            {  
                for (int n = 0; n < SQLStringList.Count; n++)  
                {  
                    string strsql = SQLStringList[n].ToString();  
                    if (strsql.Trim().Length > 1)  
                    {  
                        cmd.CommandText = strsql;  
                        cmd.ExecuteNonQuery();  
                    }  
                }  
                tx.Commit();  
            }  
            catch (System.Data.SqlClient.SqlException E)  
            {  
                tx.Rollback();  
                throw new Exception(E.Message);  
            }  
        }  
    }  
 
    /// <summary>  
    /// 执行带一个存储过程参数的的SQL语句。  
    /// </summary>  
    /// <param name="SQLString">SQL语句</param>  
    /// <param name="content">参数内容,比如一个字段是格式复杂的文章，有特殊符号，可以通过这个方式添加</param>  
    /// <returns>影响的记录数</returns>  
    public static int ExecuteSql(string SQLString, string content)  
    {  
        using (SqlConnection connection = new SqlConnection(connectionString))  
        {  
            SqlCommand cmd = new SqlCommand(SQLString, connection);  
            System.Data.SqlClient.SqlParameter myParameter = new System.Data.SqlClient.SqlParameter("@content", SqlDbType.VarChar);  
 
            myParameter.Value = content;  
            cmd.Parameters.Add(myParameter);  
            try 
            {  
                connection.Open();  
                int rows = cmd.ExecuteNonQuery();  
                return rows;  
            }  
            catch (System.Data.SqlClient.SqlException E)  
            {  
                throw new Exception(E.Message);  
            }  
            finally 
            {  
                cmd.Dispose();  
                connection.Close();  
            }  
        }  
    }  
 
    /// <summary>  
    /// 向数据库里插入图像格式的字段(和上面情况类似的另一种实例)  
    /// </summary>  
    /// <param name="strSQL">SQL语句</param>  
    /// <param name="fs">图像字节,数据库的字段类型为image的情况</param>  
    /// <returns>影响的记录数</returns>  
    public static int ExecuteSqlInsertImg(string strSQL, byte[] fs)  
    {  
        using (SqlConnection connection = new SqlConnection(connectionString))  
        {  
            SqlCommand cmd = new SqlCommand(strSQL, connection);  
            System.Data.SqlClient.SqlParameter myParameter = new System.Data.SqlClient.SqlParameter("@fs", SqlDbType.Binary);  
            myParameter.Value = fs;  
            cmd.Parameters.Add(myParameter);  
            try 
            {  
                connection.Open();  
                int rows = cmd.ExecuteNonQuery();  
                return rows;  
            }  
            catch (System.Data.SqlClient.SqlException E)  
            {  
                throw new Exception(E.Message);  
            }  
            finally 
            {  
                cmd.Dispose();  
                connection.Close();  
            }  
        }  
    }  
 
    /// <summary>  
    /// 执行一条计算查询结果语句，返回查询结果（object）。  
    /// </summary>  
    /// <param name="SQLString">计算查询结果语句</param>  
    /// <returns>查询结果（object）</returns>  
    public static object GetSingle(string SQLString)  
    {  
        using (SqlConnection connection = new SqlConnection(connectionString))  
        {  
            using (SqlCommand cmd = new SqlCommand(SQLString, connection))  
            {  
                try 
                {  
                    connection.Open();  
                    object obj = cmd.ExecuteScalar();  
                    if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))  
                    {  
                        return null;  
                    }  
                    else 
                    {  
                        return obj;  
                    }  
                }  
                catch (System.Data.SqlClient.SqlException e)  
                {  
                    connection.Close();  
                    throw new Exception(e.Message);  
                }  
            }  
        }  
    }  
 
    /// <summary>  
    /// 执行查询语句，返回SqlDataReader  
    /// </summary>  
    /// <param name="strSQL">查询语句</param>  
    /// <returns>SqlDataReader</returns>  
    public static SqlDataReader ExecuteReader(string strSQL)  
    {  
        SqlConnection connection = new SqlConnection(connectionString);  
        SqlCommand cmd = new SqlCommand(strSQL, connection);  
        try 
        {  
            connection.Open();  
            SqlDataReader myReader = cmd.ExecuteReader();  
            return myReader;  
        }  
        catch (System.Data.SqlClient.SqlException e)  
        {  
            throw new Exception(e.Message);  
        }  
 
    }  
 
    /// <summary>  
    /// 执行查询语句，返回DataSet  
    /// </summary>  
    /// <param name="SQLString">查询语句</param>  
    /// <returns>DataSet</returns>  
    public static DataSet Query(string SQLString)  
    {  
        using (SqlConnection connection = new SqlConnection(connectionString))  
        {  
            DataSet ds = new DataSet();  
            try 
            {  
                connection.Open();  
                SqlDataAdapter command = new SqlDataAdapter(SQLString, connection);  
 
                command.Fill(ds, "ds");  
            }  
            catch (System.Data.SqlClient.SqlException ex)  
            {  
                throw new Exception(ex.Message);  
            }  
            return ds;  
        }  
    }  
 
    /// <summary>  
    /// 执行查询语句，返回datatable  
    /// </summary>  
    /// <param name="SQLString">查询语句</param>  
    /// <returns>DataSet</returns>  
    public static DataTable QueryTable(string SQLString)  
    {  
        using (SqlConnection connection = new SqlConnection(connectionString))  
        {  
            DataSet ds = new DataSet();  
            try 
            {  
                connection.Open();  
                SqlDataAdapter command = new SqlDataAdapter(SQLString, connection);  
                command.Fill(ds, "ds");  
            }  
            catch (System.Data.SqlClient.SqlException ex)  
            {  
                throw new Exception(ex.Message);  
            }  
            return ds.Tables[0];  
        }  
    } 
    #endregion 
 
    #region 执行带参数的SQL语句  
    /// <summary>  
    /// 执行SQL语句，返回影响的记录数  
    /// </summary>  
    /// <param name="SQLString">SQL语句</param>  
    /// <returns>影响的记录数</returns>  
    public static int ExecuteSql(string SQLString, params SqlParameter[] cmdParms)  
    {  
        using (SqlConnection connection = new SqlConnection(connectionString))  
        {  
            using (SqlCommand cmd = new SqlCommand())  
            {  
                try 
                {  
                    PrepareCommand(cmd, connection, null, SQLString, cmdParms);  
                    int rows = cmd.ExecuteNonQuery();  
                    cmd.Parameters.Clear();  
                    return rows;  
                }  
                catch (System.Data.SqlClient.SqlException E)  
                {  
                    throw new Exception(E.Message);  
                }  
            }  
        }  
    }  
 
    /// <summary>  
    /// 执行多条SQL语句，实现数据库事务。  
    /// </summary>  
    /// <param name="SQLStringList">SQL语句的哈希表（key为sql语句，value是该语句的SqlParameter[]）</param>  
    public static void ExecuteSqlTran(Hashtable SQLStringList)  
    {  
        using (SqlConnection conn = new SqlConnection(connectionString))  
        {  
            conn.Open();  
            using (SqlTransaction trans = conn.BeginTransaction())  
            {  
                SqlCommand cmd = new SqlCommand();  
                try 
                {  
                    //循环  
                    foreach (DictionaryEntry myDE in SQLStringList)  
                    {  
                        string cmdText = myDE.Key.ToString();  
                        SqlParameter[] cmdParms = (SqlParameter[])myDE.Value;  
                        PrepareCommand(cmd, conn, trans, cmdText, cmdParms);  
                        int val = cmd.ExecuteNonQuery();  
                        cmd.Parameters.Clear();  
 
                        trans.Commit();  
                    }  
                }  
                catch 
                {  
                    trans.Rollback();  
                    throw;  
                }  
            }  
        }  
    }  
 
    /// <summary>  
    /// 执行一条计算查询结果语句，返回查询结果（object）。  
    /// </summary>  
    /// <param name="SQLString">计算查询结果语句</param>  
    /// <returns>查询结果（object）</returns>  
    public static object GetSingle(string SQLString, params SqlParameter[] cmdParms)  
    {  
        using (SqlConnection connection = new SqlConnection(connectionString))  
        {  
            using (SqlCommand cmd = new SqlCommand())  
            {  
                try 
                {  
                    PrepareCommand(cmd, connection, null, SQLString, cmdParms);  
                    object obj = cmd.ExecuteScalar();  
                    cmd.Parameters.Clear();  
                    if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))  
                    {  
                        return null;  
                    }  
                    else 
                    {  
                        return obj;  
                    }  
                }  
                catch (System.Data.SqlClient.SqlException e)  
                {  
                    throw new Exception(e.Message);  
                }  
            }  
        }  
    }  
 
    /// <summary>  
    /// 执行查询语句，返回SqlDataReader  
    /// </summary>  
    /// <param name="strSQL">查询语句</param>  
    /// <returns>SqlDataReader</returns>  
    public static SqlDataReader ExecuteReader(string SQLString, params SqlParameter[] cmdParms)  
    {  
        SqlConnection connection = new SqlConnection(connectionString);  
        SqlCommand cmd = new SqlCommand();  
        try 
        {  
            PrepareCommand(cmd, connection, null, SQLString, cmdParms);  
            SqlDataReader myReader = cmd.ExecuteReader();  
            cmd.Parameters.Clear();  
            return myReader;  
        }  
        catch (System.Data.SqlClient.SqlException e)  
        {  
            throw new Exception(e.Message);  
        }  
 
    }  
 
    /// <summary>  
    /// 执行查询语句，返回DataSet  
    /// </summary>  
    /// <param name="SQLString">查询语句</param>  
    /// <returns>DataSet</returns>  
    public static DataSet Query(string SQLString, params SqlParameter[] cmdParms)  
    {  
        using (SqlConnection connection = new SqlConnection(connectionString))  
        {  
            SqlCommand cmd = new SqlCommand();  
            PrepareCommand(cmd, connection, null, SQLString, cmdParms);  
            using (SqlDataAdapter da = new SqlDataAdapter(cmd))  
            {  
                DataSet ds = new DataSet();  
                try 
                {  
                    da.Fill(ds, "ds");  
                    cmd.Parameters.Clear();  
                }  
                catch (System.Data.SqlClient.SqlException ex)  
                {  
                    throw new Exception(ex.Message);  
                }  
                return ds;  
            }  
        }  
    }  
 
    public static DataTable QueryTable(string SQLString, params SqlParameter[] cmdParms)  
    {  
        using (SqlConnection connection = new SqlConnection(connectionString))  
        {  
            SqlCommand cmd = new SqlCommand();  
            PrepareCommand(cmd, connection, null, SQLString, cmdParms);  
            using (SqlDataAdapter da = new SqlDataAdapter(cmd))  
            {  
                DataSet ds = new DataSet();  
                try 
                {  
                    da.Fill(ds, "ds");  
                    cmd.Parameters.Clear();  
                }  
                catch (System.Data.SqlClient.SqlException ex)  
                {  
                    throw new Exception(ex.Message);  
                }  
                return ds.Tables[0];  
            }  
        }  
    }  
 
    private static void PrepareCommand(SqlCommand cmd, SqlConnection conn, SqlTransaction trans, string cmdText, SqlParameter[] cmdParms)  
    {  
        if (conn.State != ConnectionState.Open)  
            conn.Open();  
        cmd.Connection = conn;  
        cmd.CommandText = cmdText;  
        if (trans != null)  
            cmd.Transaction = trans;  
        cmd.CommandType = CommandType.Text;//cmdType;  
        if (cmdParms != null)  
        {  
            foreach (SqlParameter parm in cmdParms)  
                cmd.Parameters.Add(parm);  
        }  
    } 
    #endregion 
 
    #region 存储过程操作  
    /// <summary>  
    /// 执行存储过程  
    /// </summary>  
    /// <param name="storedProcName">存储过程名</param>  
    /// <param name="parameters">存储过程参数</param>  
    /// <returns>SqlDataReader</returns>  
    public static SqlDataReader RunProcedure(string storedProcName, IDataParameter[] parameters)  
    {  
        SqlConnection connection = new SqlConnection(connectionString);  
        SqlDataReader returnReader;  
        connection.Open();  
        SqlCommand command = BuildQueryCommand(connection, storedProcName, parameters);  
        command.CommandType = CommandType.StoredProcedure;  
        returnReader = command.ExecuteReader();  
        return returnReader;  
    }  
 
    /// <summary>  
    /// 执行存储过程  
    /// </summary>  
    /// <param name="storedProcName">存储过程名</param>  
    /// <param name="parameters">存储过程参数</param>  
    /// <param name="tableName">DataSet结果中的表名</param>  
    /// <returns>DataSet</returns>  
    public static DataSet RunProcedure(string storedProcName, IDataParameter[] parameters, string tableName)  
    {  
        using (SqlConnection connection = new SqlConnection(connectionString))  
        {  
            DataSet dataSet = new DataSet();  
            connection.Open();  
            SqlDataAdapter sqlDA = new SqlDataAdapter();  
            sqlDA.SelectCommand = BuildQueryCommand(connection, storedProcName, parameters);  
            sqlDA.Fill(dataSet, tableName);  
            connection.Close();  
            return dataSet;  
        }  
    }  
 
    /// <summary>  
    /// 构建 SqlCommand 对象(用来返回一个结果集，而不是一个整数值)  
    /// </summary>  
    /// <param name="connection">数据库连接</param>  
    /// <param name="storedProcName">存储过程名</param>  
    /// <param name="parameters">存储过程参数</param>  
    /// <returns>SqlCommand</returns>  
    private static SqlCommand BuildQueryCommand(SqlConnection connection, string storedProcName, IDataParameter[] parameters)  
    {  
        SqlCommand command = new SqlCommand(storedProcName, connection);  
        command.CommandType = CommandType.StoredProcedure;  
        foreach (SqlParameter parameter in parameters)  
        {  
            command.Parameters.Add(parameter);  
        }  
        return command;  
    }  
 
    /// <summary>  
    /// 执行存储过程，返回影响的行数        
    /// </summary>  
    /// <param name="storedProcName">存储过程名</param>  
    /// <param name="parameters">存储过程参数</param>  
    /// <param name="rowsAffected">影响的行数</param>  
    /// <returns></returns>  
    public static int RunProcedure(string storedProcName, IDataParameter[] parameters, out int rowsAffected)  
    {  
        using (SqlConnection connection = new SqlConnection(connectionString))  
        {  
            int result;  
            connection.Open();  
            SqlCommand command = BuildIntCommand(connection, storedProcName, parameters);  
            rowsAffected = command.ExecuteNonQuery();  
            result = (int)command.Parameters["ReturnValue"].Value;  
            //Connection.Close();  
            return result;  
        }  
    }  
 
    /// <summary>  
    /// 创建 SqlCommand 对象实例(用来返回一个整数值)     
    /// </summary>  
    /// <param name="storedProcName">存储过程名</param>  
    /// <param name="parameters">存储过程参数</param>  
    /// <returns>SqlCommand 对象实例</returns>  
    private static SqlCommand BuildIntCommand(SqlConnection connection, string storedProcName, IDataParameter[] parameters)  
    {  
        SqlCommand command = BuildQueryCommand(connection, storedProcName, parameters);  
        command.Parameters.Add(new SqlParameter("ReturnValue",  
            SqlDbType.Int, 4, ParameterDirection.ReturnValue,  
            false, 0, 0, string.Empty, DataRowVersion.Default, null));  
        return command;  
    } 
    #endregion  
}  
 
从微软官方下的SqlHelper代码和例子，调试运行了代码，总算跑通，基本可以看懂，不过还是不太会用，只好暂时使用以前的SqlHelper.cs了。官方下的SqlHelper.cs代码和例子，过段时间传上 

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