[转]MySQLHelper类

本文转自：http://de.cel.blog.163.com/blog/static/5145123620110181003903/

类似于SQLHelper，只是这里引用的是MySql.Data类库，而不是System.Data.SqlClient;因为.Net框架里面并不包 含些类库，好在咱们有强大的网友有做好的MySql.Data类库。在网上一搜MySql.Data就可以找到的。注意一定要先添加对 MySql.Data的引用哦，接下来是MySQLHelper的类库代码。

using System.Data;
using MySql.Data.MySqlClient;

namespace MySQLHelper
{

/// <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();

//public static readonly string DBConnectionString =
"Server=localhost;DataBase=menagerie;Uid=de.cel;Pwd=de.cel";  
//在MySql中localhost好像不能用"."代替，我试了一下，会出错。
        #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

}