Setting the AutoMode property to
True will automatically execute Pervasive PSQL extended fetch operations (GetNextExtended) to retrieve the data specified in the
SelectedFields and
SelectedRecords properties as soon as the
Init method is called at run time. GetNextExtended operations require logical currency. You may establish logical currency by invoking any of the indexed record operations such as GetFirst, GetEqual, and so on.
If AutoMode is set to
True, then records which meet the selection criteria are fetched automatically and cached as a snapshot of the record set in memory as
Row values are requested. Extended methods are disabled if
AutoMode is set to
True. If the
CancelDialog property is
True, then a Cancel dialog box will be displayed to the user during data access operations at run time, allowing the user to cancel the process.
When AutoMode is set to
True, any attempt to use extended operations will return a
-1 status at run time. See
ExtendedOps.
If the AutoMode property is set to
False, then data retrieval is your responsibility. Calling the
Init method simply allocates the structures used by Pervasive PSQL for extended operations calls, but no data retrieval is performed. You can fetch data from the file by performing a
GetNextExtended,
GetPreviousExtended,
StepNextExtended or
StepPreviousExtended method at run time. Only one extended operations cache buffer is retained in memory, and is re-used for subsequent fetches.
The ExtendedOps property must be set to
True to enable the extended operations capabilities of the VAccess control.
Affects: GetNextExtended, GetPreviousExtended, StepNextExtended, StepPreviousExtended, Init, Row