Fetching a Single Row with IRow
The IRow interface implementation in the SQL Server Native Client OLE DB provider is simplified to increase performance. IRow allows direct access to columns of a single row object. If you know beforehand that the result of a command execution will produce exactly one row, IRow will retrieve the columns of that row. If the result set includes multiple rows, IRow will expose only the first row.
The IRow implementation does not allow any navigation of the row. Each column in the row is accessed only one time with one exception: A column can be accessed one time to find the column size and again to fetch the data.
To obtain a row object using ICommand::Execute method, IID_IRow must be passed. The IMultipleResults interface must be used to handle multiple result sets. IMultipleResults supports IRow and IRowset. IRowset is used for bulk operations.