Advances the FbDataReader to the next record.
true if there are more rows; otherwise, false.
The default position of the FbDataReader is prior to the first record. Therefore, you must call Read to begin accessing any data.
Only one FbDataReader per FbConnection can be open at a time, and any attempt to open another will fail until the first one is closed. Similarly, while the FbDataReader is in use, the associated FbConnection is busy serving it until you close the FbDataReader by call Close method.
FbDataReader Class | FirebirdSql.Data.Firebird Namespace