在C# 程序里，我想要一个MySqlHelper.cs类，有的请进来，谢谢

不能通过 SqlHelper.cs该一个出来？别什么都来求！

这是DB类.连接数据库的..
还需要一个APP.config配置文件<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <appSettings>
    <add key="SQLCONNECTIONSTRING" value="server=.\SQLEXPRESS;uid=你的;pwd=你的;database=数据库"/>
  </appSettings>
</configuration>using System;
using System.Collections.Generic;
using System.Text;
using System.Data.SqlClient;
using System.Data;namespace DAL
{
   public class DBHelp
   {
       public SqlConnection Connection;//数据库连接
       public string connectionString;
       public bool m_bln;            //函数执行成功的标志
       public int rows;              //返回执行后，记录的行数
       public DBHelp()
       {
           connectionString = System.Configuration.ConfigurationSettings.AppSettings["SQLCONNECTIONSTRING"].ToString();
           //connectionString = System.Configuration.ConfigurationManager.AppSettings["SQLCONNECTIONSTRING"].ToString();
           //connectionString = ConfigurationManager.ConnectionStrings["SQLCONNECTIONSTRING"].ConnectionString.ToString();
           Connection = new SqlConnection(connectionString);
       }
       public int ExecuteCommand(string sql)
       {
           int relust = 0;
           if (Connection.State != ConnectionState.Open)
               Connection.Open();
           using (SqlCommand command = new SqlCommand(sql, Connection))
           {               command.CommandTimeout = 0;
               relust = command.ExecuteNonQuery();
           }
           return relust;
       }
       public bool ExecuteOperateData(string sql)
       {
           try
           {
               if (Connection.State != ConnectionState.Open)
                   Connection.Open();
               SqlCommand cmd = Connection.CreateCommand();
               //SqlCommand coom = new SqlCommand(sql, Connection);
               //coom.ExecuteNonQuery();
               cmd.CommandType = CommandType.Text;
               cmd.CommandText = sql;
               rows = cmd.ExecuteNonQuery();
               //  Connection.Dispose();
               m_bln = true;
               return m_bln;
           }
           catch//(Exception ex)
           {
               //MessageBox.Show(ex.ToString());
               m_bln = false;
               return m_bln;
           }
       }
       public DataTable ReturnRs(string sql)
       {
           DataSet ds = new DataSet();
           DataTable dt = new DataTable();
           try
           {
               if (Connection.State != ConnectionState.Open) Connection.Open();
               SqlDataAdapter sqlDA = new SqlDataAdapter();
               sqlDA.SelectCommand = new SqlCommand(sql, Connection);
               sqlDA.Fill(ds);
               dt = ds.Tables[0];           }
           catch//(Exception ex)
           {
               //MessageBox.Show(ex.ToString());
               dt = null;
           }
           finally
           {               Connection.Close();
           }
           return dt;
       }
       public string OneResult(string sql)
       {
           if (Connection.State != ConnectionState.Open) Connection.Open();
           SqlCommand cmd = Connection.CreateCommand();
           cmd.CommandType = CommandType.Text;
           cmd.CommandText = sql;
           string theResult = "";
           if (cmd.ExecuteScalar() != null)
           {
               theResult = cmd.ExecuteScalar().ToString();           }
           Connection.Close();
           return theResult;
       }
       public DataTable exeonesql(string sql)
       {
           SqlDataAdapter da;
           DataSet ds;
           if (Connection.State != ConnectionState.Open) Connection.Open();
           using (SqlCommand cmd = new SqlCommand(sql, Connection))
           {
               da = new SqlDataAdapter(cmd);
               ds = new DataSet();
               da.Fill(ds);
           }
           Connection.Close();
           da.Dispose();
           return ds.Tables[0];
       }
    }
}
你自己有什么地方可能需要改一下.

这个简单。引用MySql.Data.dll 上网找，找不到找我。再找MYSqlHelper.cs 找不到找我

你好，我找到了，现在有个问题是：
MySqlCommand cmd = new MySqlCommand();
XmlReader retval = cmd.ExecuteXmlReader();
为什么 MySqlCommand的对象点不出来ExecuteXmlReader()这个方法，能不能帮我解决一下？

MySQLConnection conn = new MySQLConnection( new MySQLConnectionString("localhost","","root","").AsString );
conn.Open();
MySQLCommand cmd;
cmd = new MySQLDriverCS.MySQLCommand("",conn);
Mysql 操作类

using System;
using System.Collections.Generic;
using System.Text;
using System.Data.SqlClient;
using System.Configuration;
using System.Data;
using System.Collections;
using System.Net;///SQL的帮助类，用来执行数据库操作语句
///作者：汤雄
///时间：2009年5月29日namespace AccessSQL
{
    public class SQLHelper
    {

        public static string ConnectionString = "Data Source=192.168.0.37;uid=sa;pwd=sa;Initial Catalog=aaaao";
        public static SqlConnection conn = new SqlConnection(ConnectionString);
        //
        /// <summary>
        /// Execute a SqlCommand (that returns no resultset) against the database specified in the connection string
        /// using the provided parameters.
        /// </summary>
        /// <res>
        /// e.g.:
        ///  int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));
        /// </res>
        /// <param name="connectionString">a valid connection string for a SqlConnection</param>
        /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">the stored procedure name or T-SQL command</param>
        /// <param name="commandParameters">an array of SqlParamters used to execute the command</param>
        /// <returns>an int representing the number of rows affected by the command</returns>
        public static bool Open()
        {
            try
            {
                if (conn.State != ConnectionState.Open)
                    conn.Open();
                return true;
            }
            catch
            {
                return false;
            }
        }
        public static bool Closed()
        {
            try
            {
                if (conn.State != ConnectionState.Closed)
                    conn.Close();
                return true;
            }
            catch
            {
                return false;
            }
        }
        public static int ExecuteNonQuery(string connectionString, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
        {            SqlCommand cmd = new SqlCommand();
            try
            {

                    PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);
                    int val = cmd.ExecuteNonQuery();
                    cmd.Parameters.Clear();
                    return val;


            }
            catch(Exception e)
            {
                return 0;
            }
            finally
            {
                cmd.Parameters.Clear();

            }
        }
                /// <summary>
        /// Execute a SqlCommand (that returns no resultset) using an existing SQL Transaction
        /// using the provided parameters.
        /// </summary>
        /// <res>
        /// e.g.:
        ///  int result = ExecuteNonQuery(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));
        /// </res>
        /// <param name="trans">an existing sql transaction</param>
        /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">the stored procedure name or T-SQL command</param>
        /// <param name="commandParameters">an array of SqlParamters used to execute the command</param>
        /// <returns>an int representing the number of rows affected by the command</returns>
        public static int ExecuteNonQuery(SqlTransaction trans, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
        {
            SqlCommand cmd = new SqlCommand();
            PrepareCommand(cmd, trans.Connection, trans, cmdType, cmdText, commandParameters);
            int val = cmd.ExecuteNonQuery();
            cmd.Parameters.Clear();
            return val;
        }        /// <summary>
        /// Execute a SqlCommand that returns a resultset against the database specified in the connection string
        /// using the provided parameters.
        /// </summary>
        /// <res>
        /// e.g.:
        ///  SqlDataReader r = ExecuteReader(connString, CommandType.StoredProcedure, "PublishOrders", new SqlParameter("@prodid", 24));
        /// </res>
        /// <param name="connectionString">a valid connection string for a SqlConnection</param>
        /// <param name="commandType">the CommandType (stored procedure, text, etc.)</param>
        /// <param name="commandText">the stored procedure name or T-SQL command</param>
        /// <param name="commandParameters">an array of SqlParamters used to execute the command</param>
        /// <returns>A SqlDataReader containing the results</returns>
        public static SqlDataReader ExecuteReader(string connectionString, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
        {
            SqlCommand cmd = new SqlCommand();
           // SqlConnection conn = new SqlConnection(connectionString);            // we use a try/catch here because if the method throws an exception we want to
            // close the connection throw code, because no datareader will exist, hence the
            // commandBehaviour.CloseConnection will not work
            try
            {
                PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);
                SqlDataReader rdr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
                cmd.Parameters.Clear();
                return rdr;
            }
            catch
            {

                conn.Close();
                throw;
            }
        }        public static SqlDataAdapter ExecuteAdapter(string connectionString, string cmdText, params SqlParameter[] commandParameters)
        {
            SqlCommand cmd = new SqlCommand();

            PrepareCommand(cmd, conn, null, CommandType.Text, cmdText, commandParameters);
            try
            {
                SqlDataAdapter da = new SqlDataAdapter();
                da.SelectCommand = cmd;
                return da;
            }
            catch
            {
                conn.Close();
                throw;
            }
        }        /// <summary>
        /// Prepare a command for execution
        /// </summary>
        /// <param name="cmd">SqlCommand object</param>
        /// <param name="conn">SqlConnection object</param>
        /// <param name="trans">SqlTransaction object</param>
        /// <param name="cmdType">Cmd type e.g. stored procedure or text</param>
        /// <param name="cmdText">Command text, e.g. Select * from Products</param>
        /// <param name="cmdParms">SqlParameters to use in the command</param>
        private static void PrepareCommand(SqlCommand cmd, SqlConnection conn, SqlTransaction trans, CommandType cmdType, 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 = cmdType;            if (cmdParms != null)
            {
                foreach (SqlParameter parm in cmdParms)
                    cmd.Parameters.Add(parm);
            }
        }
           }
}

楼上的。。人家说的是 mysql楼主可以看看这个： http://sourceforge.net/projects/mysqldrivercs/

我是来拿分的using System;
using System.Collections;
using System.Collections.Specialized;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;
        public static string connectionString = "Data Source=192.168.1.235;Initial Catalog=jnbuild;Persist Security Info=True;User ID=sa;Password=sa";

        public SqlHelper()
        {        }        #region 公用方法
        /// <summary>
        /// 获取某个表的数量
        /// </summary>
        /// <param name="field">主键</param>
        /// <param name="tableName">表名</param>
        /// <param name="where">条件</param>
        /// <returns></returns>
        public static int GetDataRecordCount(string field, string tableName, string where)
        {
            string strsql = "select count(" + field + ") from " + tableName;
            if (where != "")
            {
                strsql += " where " + where;
            }
            object obj = SqlHelper.GetSingle(strsql);
            if (obj == null)
            {
                return 1;
            }
            else
            {
                return int.Parse(obj.ToString());
            }
        }
        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);
                        //ITNB.Base.Error.showError(E.Message.ToString());
                    }
                }
            }
        }        /// <summary>
        /// 执行SQL语句，设置命令的执行等待时间
        /// </summary>
        /// <param name="SQLString"></param>
        /// <param name="Times"></param>
        /// <returns></returns>
        public static int ExecuteSqlByTime(string SQLString, int Times)
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                using (SqlCommand cmd = new SqlCommand(SQLString, connection))
                {
                    try
                    {
                        connection.Open();
                        cmd.CommandTimeout = Times;
                        int rows = cmd.ExecuteNonQuery();
                        return rows;
                    }
                    catch (System.Data.SqlClient.SqlException E)
                    {
                        connection.Close();
                        throw new Exception(E.Message);
                        // ITNB.Base.Error.showError(E.Message.ToString());
                    }
                }
            }
        }        /// <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);
                    //    ITNB.Base.Error.showError(E.Message.ToString());
                }
            }
        }
        /// <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.NText);
                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);
                    //   ITNB.Base.Error.showError(E.Message.ToString());
                }
                finally
                {
                    cmd.Dispose();
                    connection.Close();
                }
            }
        }

/// 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 object ExecuteSqlGet(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.NText);
                myParameter.Value = content;
                cmd.Parameters.Add(myParameter);
                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)
                {
                    throw new Exception(E.Message);
                    // ITNB.Base.Error.showError(E.Message.ToString());
                }
                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.Image);
                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);
                    //ITNB.Base.Error.showError(E.Message.ToString());
                }
                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);
                        //  ITNB.Base.Error.showError(e.Message.ToString());
                    }
                }
            }
        }
        /// <summary>
        /// 执行查询语句，返回SqlDataReader(使用该方法切记要手工关闭SqlDataReader和连接)
        /// </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);
                // ITNB.Base.Error.showError(e.Message.ToString());
            }
            //finally //不能在此关闭，否则，返回的对象将无法使用
            //{
            //  cmd.Dispose();
            //  connection.Close();
            //}
        }
        /// <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 E)
                {
                    throw new Exception(E.Message);
                    //   ITNB.Base.Error.showError(E.Message.ToString());
                }
                return ds;
            }
        }
        /// <summary>
        /// 执行查询语句，返回DataSet,设置命令的执行等待时间
        /// </summary>
        /// <param name="SQLString"></param>
        /// <param name="Times"></param>
        /// <returns></returns>
        public static DataSet Query(string SQLString, int Times)
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                DataSet ds = new DataSet();
                try
                {
                    connection.Open();
                    SqlDataAdapter command = new SqlDataAdapter(SQLString, connection);
                    command.SelectCommand.CommandTimeout = Times;
                    command.Fill(ds, "ds");
                }
                catch (System.Data.SqlClient.SqlException E)
                {
                    throw new Exception(E.Message);
                    //  ITNB.Base.Error.showError(ex.Message.ToString());
                }
                return ds;
            }
        }

        /// <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);
                        // ITNB.Base.Error.showError(e.Message.ToString());
                    }
                }
            }
        }        /// <summary>
        /// 执行查询语句，返回SqlDataReader (使用该方法切记要手工关闭SqlDataReader和连接)
        /// </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);
                // ITNB.Base.Error.showError(e.Message.ToString());
            }
            //finally //不能在此关闭，否则，返回的对象将无法使用
            //{
            //  cmd.Dispose();
            //  connection.Close();
            //}             }        /// <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 E)
                    {
                        throw new Exception(E.Message);
                        //  ITNB.Base.Error.showError(ex.Message.ToString());
                    }
                    return ds;
                }
            }
        }
        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 parameter in cmdParms)
                {
                    if ((parameter.Direction == ParameterDirection.InputOutput || parameter.Direction == ParameterDirection.Input) &&
                        (parameter.Value == null))
                    {
                        parameter.Value = DBNull.Value;
                    }
                    cmd.Parameters.Add(parameter);
                }
            }
        }        #endregion        #region 存储过程操作        /// <summary>
        /// 执行存储过程  (使用该方法切记要手工关闭SqlDataReader和连接)
        /// </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();
            //Connection.Close(); 不能在此关闭，否则，返回的对象将无法使用
            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;
            }
        }
        public static DataSet RunProcedure(string storedProcName, IDataParameter[] parameters, string tableName, int Times)
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                DataSet dataSet = new DataSet();
                connection.Open();
                SqlDataAdapter sqlDA = new SqlDataAdapter();
                sqlDA.SelectCommand = BuildQueryCommand(connection, storedProcName, parameters);
                sqlDA.SelectCommand.CommandTimeout = Times;
                sqlDA.Fill(dataSet, tableName);
                connection.Close();
                return dataSet;
            }
        }
        /// <summary>
        /// 执行存储过程后返回执行结果（标识）
        /// </summary>
        /// <param name="storedProcName"></param>
        /// <param name="parameters"></param>
        /// <returns></returns>
        public static string RunProcedureState(string storedProcName, IDataParameter[] parameters)
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {                connection.Open();
                SqlDataAdapter sqlDA = new SqlDataAdapter();
                sqlDA.SelectCommand = BuildQueryCommand(connection, storedProcName, parameters);
                sqlDA.SelectCommand.Parameters.Add(new SqlParameter("ReturnValue", SqlDbType.Int, 4, ParameterDirection.ReturnValue, false, 0, 0, string.Empty, DataRowVersion.Default, null)); //增加存储过程的返回值参数
                sqlDA.SelectCommand.ExecuteNonQuery();
                connection.Close();
                return sqlDA.SelectCommand.Parameters["ReturnValue"].Value.ToString();
            }
        }

好几个人的都是回复的 sql的，我要的是MySql 的，不过还是谢谢了，还是值得大家学习的，刚刚我仔细的查了查，MySql public static XmlReader ExecuteXmlReader(MySqlTransaction transaction, CommandType commandType, string commandText, params MySqlParameter[] 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
            MySqlCommand cmd = new MySqlCommand();
            MySqlCommand c = new MySqlCommand ();
            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;
        }是在  XmlReader retval = cmd.ExecuteXmlReader();这个地方的时候点不出来ExecuteXmlReader()方法，不知道 MySqlCommand 这个类里有没有，我查了查资料也没有搞清楚，希望大家看清楚问题，谢谢了

调试易

在C# 程序里，我想要一个MySqlHelper.cs类，有的请进来，谢谢

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