... System .Data System .Data , , System .Data. CommonSystem .Data. Common, , System .Data. OleDbSystem .Data. OleDb, , System .Data. SqlClientSystem .Data. SqlClient, , System .Data. SqlTypesSystem .Data. SqlTypes..––CCááccllớớppcơcơbbảảnntrongtrongSystem .Data System .Data : ... , SqlConnectionSqlConnection, , OleDbConnectionOleDbConnection, , SqlDataAdapterSqlDataAdapter, , OleDbDataAdapterOleDbDataAdapter, , SqlDataReaderSqlDataReader, , OleDbDataReaderOleDbDataReader, ... connconn););SqlDataAdapterSqlDataAdapteradapter = new adapter = new SqlDataAdapterSqlDataAdapter();();adapter.SelectCommandadapter.SelectCommand= = cmdcmd;;DataSetDataSet data = new data...