using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Data; using System.Data.SqlClient; using System.Configuration; using MySql.Data.MySqlClient; namespace DAL {   public class GetConnection     {         private static MySqlConnection  _connection;       /// <summary>       /// 获取数据库连接桥       /// </summary>         private static MySqlConnection Connection         {             get             {                //string connectionString = ConfigurationManager.AppSettings["ConnectionString"];                 string connectionString = "server=localhost;user id=root; password=root; database=system; pooling=false";                 //server=222.222.222.222;port=3306;uid=user;pwd=;database=basename;远程连接的                 //string connectionString = "Data Source=202.192.72.22;Initial Catalog=wwj;Persist Security Info=True;User ID=wwj;Password=wwj123";                 if (_connection == null)                 {                     _connection = new MySqlConnection(connectionString);                     _connection.Open();                 }                 if (_connection.State == ConnectionState.Closed)                 {                     _connection.Open();                 }                 if (_connection.State == ConnectionState.Broken)                 {                     _connection.Close();                     _connection.Open();                 }                 return GetConnection._connection;             }         }       /// <summary>       /// 获取表数据       /// </summary>       /// <param name="sql"></param>       /// <returns></returns>         public static MySqlDataReader GetDataRead(string sql)         {             MySqlCommand command = new MySqlCommand(sql, Connection);             MySqlDataReader read = command.ExecuteReader();             return read;         }         public static int NoSelect(string sql)         {             MySqlCommand command = new MySqlCommand(sql, Connection);             int row = command.ExecuteNonQuery();             return row;         }         public static DataTable GetDataTable(string sql)         {             MySqlCommand command = new MySqlCommand(sql, Connection);             DataTable dt = new DataTable();             MySqlDataAdapter sda = new MySqlDataAdapter(command);             sda.Fill(dt);             return dt;         }         /// <summary>         /// 执行sql语句，返回一行一列。。         /// </summary>         /// <param name="sql">SQL语句</param>         /// <returns></returns>         public static string GetScalar(string sql)         {             MySqlCommand command = new MySqlCommand(sql, Connection);             return command.ExecuteScalar().ToString();         }     } }