Re: [DUG]: TAggregateField

[Paul Mckenzie]

Aggreed, design limitation. It would be nice to be able to have a TAggregateField of a type eg TIntegerField, TStringField, etc... The null is returned because TAggregateField is a type Variant not an IntegerField (the expression - which could be anything is never evaluated!). There are no records - thus expression of the Aggregate Field is not evaluated (I think, I considers no records = no data for evaluation) I have converted to a Calculated Field, I can make it an IintegerField.   Regards Paul McKenzie Analyst Programmer SMSS ltd.   ----- Original Message ----- From: Neven MacEwan To: Multiple recipients of list delphi Sent: Thursday, October 17, 2002 9:42 AM Subject: Re: [DUG]: TAggregateField Paul   Interesting,  tho I would suggest that this is not exactly a bug but definately a design limitation, Since the AggFields belong to the dataset not the record, and count(*) should return 0 not NULL on an empty dataset   Neven From: Paul Mckenzie To: Multiple recipients of list delphi Sent: Thursday, October 17, 2002 8:49 AM Subject: Re: [DUG]: TAggregateField No one replied - but I managed to figure it out ... for those interested: In the VCL, if the DataSet is Empty (IsEmpty = True) the AggregateField is never evaluated - Null is returned. TAggregateFields are untyped (variant) unlike Calculated Fields which are typed. When thought about - the TAggregateField is a "Field" belonging to a "Record" - how can one have a field without a record.     Regards Paul McKenzie Analyst Programmer SMSS ltd.   ----- Original Message ----- From: Paul McKenzie To: Multiple recipients of list delphi Sent: Tuesday, October 15, 2002 11:43 AM Subject: [DUG]: TAggregateField G'Day   I am trying to use a TAggregateField on a Client App [AppServer accessing IB6] - the RecordCount is 0 but the TAggregateField with Expression: Count(*) returns a NULL. the field is actve. Is this normal - I thought Count(*) should always return an Integer... Am I missing something   Regards Paul McKenzie Analyst Programmer SMSS Ltd.