.net简单的三层实现功能(2)

 12             DbProviderFactory _factory = DbProviderFactories.GetFactory(providerName);
 13             DbConnection connection = _factory.CreateConnection();
 14             connection.ConnectionString = connectionString;
 15             return connection;
 16         }
 17
 18         /// <summary>
 19         /// GetCommand 获取命令参数 command 对象
 20         /// </summary>
 21         /// <param name="commandText"></param>
 22         /// <param name="commandType"></param>
 23         /// <param name="connection"></param>
 24         /// <returns></returns>
 25         private static DbCommand GetCommand(string commandText, CommandType commandType, DbConnection connection)
 26         {
 27             DbCommand command = connection.CreateCommand();
 28             command.CommandText = commandText;
 29             command.CommandType = commandType;
 30             return command;
 31         }
 32
 33         /// <summary>
 34         /// GetCommand 方法重载
 35         /// </summary>
 36         /// <param name="commandText">sql语句</param>
 37         /// <param name="connection"></param>
 38         /// <returns></returns>
 39         private static DbCommand GetCommand(string commandText, DbConnection connection)
 40         {
 41             DbCommand command = connection.CreateCommand();