C#操作MySQL的工具类MySqlHelper

    using System;  
    using System.Collections.Generic;  
    using System.Linq;  
    using System.Text;  
    using MySql.Data.MySqlClient;  
    using System.Data;  
    class MySqlHelper:IDisposable  
        {  
            private MySqlConnection m_conn = null;  
            private MySqlTransaction m_trans = null;  
            private bool m_tran_enabled = false;  
      
      
            public MySqlHelper()  
            {  
                m_conn = new MySqlConnection();  
                m_conn.ConnectionString = "Server=localhost;Port=3301;Uid=sa;Pwd=000";  
                m_conn.Open();  
            }  
      
      
            public void BeginTrans()  
            {  
                m_trans = m_conn.BeginTransaction();  
                m_tran_enabled = true;  
            }  
      
      
            public void Commit()  
            {  
                if (m_trans != null && m_tran_enabled)  
                {  
                    m_tran_enabled = false;  
                    m_trans.Commit();  
                }  
            }  
      
      
            public void Rollback()  
            {  
                if (m_trans != null && m_tran_enabled)  
                {  
                    m_tran_enabled = false;  
                    m_trans.Rollback();  
                }  
            }  
      
      
            public object QuerySome(string sql,int fieldindex)  
            {  
                using (MySqlCommand cmd = new MySqlCommand(sql,m_conn))  
                {  
                    using (MySqlDataReader sr = cmd.ExecuteReader())  
                    {  
                        if (sr.Read())  
                        {  
                            return sr.GetValue(fieldindex);  
                        }  
                    }  
                }  
                return null;  
            }  
      
      
            public delegate void FillValues(MySqlDataReader sr);  
              
            public void QuerySomes(string sql,FillValues fill)  
            {  
                using (MySqlCommand cmd = new MySqlCommand(sql,m_conn))  
                {  
                    using (MySqlDataReader sr = cmd.ExecuteReader())  
                    {  
                        fill(sr);  
                    }  
                }  
            }  
      
      
            public DataTable Source(string sql)  
            {  
                DataTable dt = null;  
                MySqlCommand cmd = null;  
                MySqlDataAdapter ad = null;  
                try  
                {  
                    lock (dt = new DataTable())  
                    {  
                        cmd = new MySqlCommand(sql,m_conn);  
                        ad = new MySqlDataAdapter((MySqlCommand)cmd);  
                        dt.Clear();  
                        ad.Fill(dt);  
                    }  
                }  
                catch (Exception e)  
                {  
                    throw e;  
                }  
                return dt;  
            }  
      
      
            public void ExecProc(string proc,params MySqlParameter[] ps)  
            {  
                using (MySqlCommand cmd = new MySqlCommand(proc,m_conn))  
                {  
                    cmd.CommandType = System.Data.CommandType.StoredProcedure;  
                    foreach (MySqlParameter p in ps)  
                    {  
                        cmd.Parameters.Add(p);  
                    }  
                    cmd.ExecuteNonQuery();  
                }  
            }  
      
      
            void IDisposable.Dispose()  
            {  
                m_conn.Close();  
                m_conn.Dispose();  
                if (m_trans != null)  
                {  
                    m_trans.Dispose();  
                }  
            }  
        }