Working with MemTableEh in the "with datadriver" mode

If TMemTableEh.DataDriver property is assigned then MemTable works in 'with datadriver' mode. In this case internal array will be created automatically when MemTableEh become active. The structure of array is delivered by the DataDriver component. 

If FetchAllOnOpen property is True then MemTableEh loads all records from DataDriver on open. If FetchAllOnOpen is False then MemTableEh will not load records until application call Next or FetchRecords methods. Method ‘Next’ checks that cursor is positioned at end of MemTableEh, if not then it fetch next record and move to the next record in provider. Method FetchRecords fetch more records from DataDriver and add it at the end of internal array of MemTable. This method takes one parameter - an amount of records which need to fetch. To fetch all record it is needed to pass ‘-1’ as parameter. When MemTable connected to DBGridEh the Grid calls FetchRecords by itself via IMemTableEh interface to display all visible records in the view area. If CachedUpdates property is False then changes are transferred right after Post method. If CachedUpdates is True then data are not transferred until the ApplyUpdates method is called.

Copyright (c) 1998-2013. All rights reserved.
What do you think about this topic? Send feedback!