C# 基于MySQL的数据层基类(MySQLHelper)

注意驱动选择MySql提供的官方驱动Connector/Net。数据库连接字符串类似这样：<add name="DBConnectString" connectionString="Server=192.168.1.2;Database=dbname;Uid=root;Pwd=111;charset=utf8" providerName="MySql.Data.MySqlClient"/>

以下是具体代码：

using System;

using System.Data;

using MySql.Data;

using MySql.Data.MySqlClient;

namespace DBUtility

{

    /// <summary>

    /// 基于MySQL的数据层基类

    /// </summary>

    /// <remarks>

    /// 参考于MS Petshop 4.0

    /// </remarks>

    public abstract class MySqlHelper

    {

        #region 数据库连接字符串

        public static readonly string DBConnectionString = System.Configuration.ConfigurationManager.ConnectionStrings["DBConnectionString"].ToString();

        #endregion

        #region PrepareCommand

        /// <summary>

        /// Command预处理

        /// </summary>

        /// <param name="conn">MySqlConnection对象</param>

        /// <param name="trans">MySqlTransaction对象，可为null</param>

        /// <param name="cmd">MySqlCommand对象</param>

        /// <param name="cmdType">CommandType，存储过程或命令行</param>

        /// <param name="cmdText">SQL语句或存储过程名</param>

        /// <param name="cmdParms">MySqlCommand参数数组，可为null</param>

        private static void PrepareCommand(MySqlConnection conn, MySqlTransaction trans, MySqlCommand cmd, CommandType cmdType, string cmdText, MySqlParameter[] 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 (MySqlParameter parm in cmdParms)

                    cmd.Parameters.Add(parm);

            }

        }

        #endregion

        #region ExecuteNonQuery

        /// <summary>

        /// 执行命令

        /// </summary>

        /// <param name="connectionString">数据库连接字符串</param>

        /// <param name="cmdType">命令类型（存储过程或SQL语句）</param>

        /// <param name="cmdText">SQL语句或存储过程名</param>

        /// <param name="cmdParms">MySqlCommand参数数组</param>

        /// <returns>返回受引响的记录行数</returns>

        public static int ExecuteNonQuery(string connectionString, CommandType cmdType, string cmdText, params MySqlParameter[] cmdParms)

        {

            MySqlCommand cmd = new MySqlCommand();

            using (MySqlConnection conn = new MySqlConnection(connectionString))

            {

                PrepareCommand(conn, null, cmd, cmdType, cmdText, cmdParms);

                int val = cmd.ExecuteNonQuery();

                cmd.Parameters.Clear();

                return val;

            }

        }

        /// <summary>

        /// 执行命令

        /// </summary>

        /// <param name="conn">Connection对象</param>

        /// <param name="cmdType">命令类型（存储过程或SQL语句）</param>

        /// <param name="cmdText">SQL语句或存储过程名</param>

        /// <param name="cmdParms">MySqlCommand参数数组</param>

        /// <returns>返回受引响的记录行数</returns>

        public static int ExecuteNonQuery(MySqlConnection conn, CommandType cmdType, string cmdText, params MySqlParameter[] cmdParms)

        {

            MySqlCommand cmd = new MySqlCommand();

            PrepareCommand(conn, null, cmd, cmdType, cmdText, cmdParms);

            int val = cmd.ExecuteNonQuery();

            cmd.Parameters.Clear();

            return val;

        }

        /// <summary>

        /// 执行事务

        /// </summary>

        /// <param name="trans">MySqlTransaction对象</param>

        /// <param name="cmdType">命令类型（存储过程或SQL语句）</param>

        /// <param name="cmdText">SQL语句或存储过程名</param>

        /// <param name="cmdParms">MySqlCommand参数数组</param>

        /// <returns>返回受引响的记录行数</returns>

        public static int ExecuteNonQuery(MySqlTransaction trans, CommandType cmdType, string cmdText, params MySqlParameter[] cmdParms)

        {

            MySqlCommand cmd = new MySqlCommand();

            PrepareCommand(trans.Connection, trans, cmd, cmdType, cmdText, cmdParms);

            int val = cmd.ExecuteNonQuery();

            cmd.Parameters.Clear();

            return val;

        }

        #endregion

        #region ExecuteScalar

        /// <summary>

        /// 执行命令，返回第一行第一列的值

        /// </summary>

        /// <param name="connectionString">数据库连接字符串</param>

        /// <param name="cmdType">命令类型（存储过程或SQL语句）</param>

        /// <param name="cmdText">SQL语句或存储过程名</param>

        /// <param name="cmdParms">MySqlCommand参数数组</param>

        /// <returns>返回Object对象</returns>

        public static object ExecuteScalar(string connectionString, CommandType cmdType, string cmdText, params MySqlParameter[] cmdParms)

        {

            MySqlCommand cmd = new MySqlCommand();

            using (MySqlConnection connection = new MySqlConnection(connectionString))

            {

                PrepareCommand(connection, null, cmd, cmdType, cmdText, cmdParms);

                object val = cmd.ExecuteScalar();

                cmd.Parameters.Clear();

                return val;

            }

        }

        /// <summary>

        /// 执行命令，返回第一行第一列的值

        /// </summary>

        /// <param name="connectionString">数据库连接字符串</param>

        /// <param name="cmdType">命令类型（存储过程或SQL语句）</param>

        /// <param name="cmdText">SQL语句或存储过程名</param>

        /// <param name="cmdParms">MySqlCommand参数数组</param>

        /// <returns>返回Object对象</returns>

        public static object ExecuteScalar(MySqlConnection conn, CommandType cmdType, string cmdText, params MySqlParameter[] cmdParms)

        {

            MySqlCommand cmd = new MySqlCommand();

            PrepareCommand(conn, null, cmd, cmdType, cmdText, cmdParms);

            object val = cmd.ExecuteScalar();

            cmd.Parameters.Clear();

            return val;

        }

        #endregion

        #region ExecuteReader

        /// <summary>

        /// 执行命令或存储过程，返回MySqlDataReader对象

        /// 注意MySqlDataReader对象使用完后必须Close以释放MySqlConnection资源

        /// </summary>

        /// <param name="connectionString">数据库连接字符串</param>

        /// <param name="cmdType">命令类型（存储过程或SQL语句）</param>

        /// <param name="cmdText">SQL语句或存储过程名</param>

        /// <param name="cmdParms">MySqlCommand参数数组</param>

        /// <returns></returns>

        public static MySqlDataReader ExecuteReader(string connectionString, CommandType cmdType, string cmdText, params MySqlParameter[] cmdParms)

        {

            MySqlCommand cmd = new MySqlCommand();

            MySqlConnection conn = new MySqlConnection(connectionString);

            try

            {

                PrepareCommand(conn, null, cmd, cmdType, cmdText, cmdParms);

                MySqlDataReader dr = cmd.ExecuteReader(CommandBehavior.CloseConnection);

                cmd.Parameters.Clear();

                return dr;

            }

            catch

            {

                conn.Close();

                throw;

            }

        }

        #endregion

        #region ExecuteDataSet

        /// <summary>

        /// 执行命令或存储过程，返回DataSet对象

        /// </summary>

        /// <param name="connectionString">数据库连接字符串</param>

        /// <param name="cmdType">命令类型(存储过程或SQL语句)</param>

        /// <param name="cmdText">SQL语句或存储过程名</param>

        /// <param name="cmdParms">MySqlCommand参数数组(可为null值)</param>

        /// <returns></returns>

        public static DataSet ExecuteDataSet(string connectionString, CommandType cmdType, string cmdText, params MySqlParameter[] cmdParms)

        {

            MySqlCommand cmd = new MySqlCommand();

            using (MySqlConnection conn = new MySqlConnection(connectionString))

            {

                PrepareCommand(conn, null, cmd, cmdType, cmdText, cmdParms);

                MySqlDataAdapter da = new MySqlDataAdapter(cmd);

                DataSet ds = new DataSet();

                da.Fill(ds);

                conn.Close();

                cmd.Parameters.Clear();

                return ds;

            }

        }

        #endregion

    }//end class

}


using System;
using System.Collections;
using System.Configuration;
using MySql.Data;
using MySql.Data.MySqlClient;
using System.Data;

namespace DBTranslater
{
    /// <summary>
    ///SQLHelper 的摘要说明
    /// </summary>
    public abstract class MySqlHelper
    {
        //数据库连接字符串
        public static string Conn = "Database='mydb';Data Source='localhost';User Id='root';Password='admin';charset='utf8'";

        // 用于缓存参数的HASH表
        private static Hashtable parmCache = Hashtable.Synchronized(new Hashtable());

        /// <summary>
        ///  给定连接的数据库用假设参数执行一个sql命令（不返回数据集）
        /// </summary>
        /// <param name="connectionString">一个有效的连接字符串</param>
        /// <param name="cmdType">命令类型(存储过程, 文本, 等等)</param>
        /// <param name="cmdText">存储过程名称或者sql命令语句</param>
        /// <param name="commandParameters">执行命令所用参数的集合</param>
        /// <returns>执行命令所影响的行数</returns>
        public static int ExecuteNonQuery(string connectionString, CommandType cmdType, string cmdText, params MySqlParameter[] commandParameters)
        {

            MySqlCommand cmd = new MySqlCommand();

            using (MySqlConnection conn = new MySqlConnection(connectionString))
            {
                PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);
                int val = cmd.ExecuteNonQuery();
                cmd.Parameters.Clear();
                return val;
            }
        }

        /// <summary>
        /// 用现有的数据库连接执行一个sql命令（不返回数据集）
        /// </summary>
        /// <param name="connection">一个现有的数据库连接</param>