How to create and use an aggregate field using TADODataset?

Question

I can create a new aggregated field (TAggregateField) with TADODataset in design mode, With the expression "Sum (MyPrice)" (MyPrice is the field in this dataset).

but this field does not display anything in the associated DBText control (it is just empty).

Can TAggregateField be used with TADODataset? (all the examples I saw were related to TClientDataSet)

Answer 1

None of the ADO dataset components shipped with Delphi support aggregated fields. They would have to implement aggregate support methods (for example GetAggregateValue) of the TDataSetancestor.

, , TAggregateField ADO ( , ), , NULL - GetAggregateValue ADO.