Hello
Too little information to understand the cause of the error.
We need to simulate it on our computer.
Can you create and send a simple demo project?
Quote:
Another question: is it possible to see the "where" clause created by STFilter?
The way the filter is applied depends on the type of DataSet and on the type of the used class TDatasetFeaturesEh
Set a breakpoint in a method
procedure TCustomDBGridEh.DefaultApplyFilter;
and further on the calls you will understand which classes are used to form the SQL expression.