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copied!<p>If you have know your to be calculated fields names at runtime, you can use something like that. </p> <pre><code>var initing:boolean; procedure TSampleForm.dsSampleAfterOpen( DataSet: TDataSet); var i:integer; dmp:tfield; begin if not initing then try initing:=true; dataset.active:=false; dataset.FieldDefs.Update; for i:=0 to dataset.FieldDefs.Count-1 do begin dmp:=DataSet.FieldDefs.Items[i].FieldClass.Create(self); dmp.FieldName:=DataSet.FieldDefs.Items[i].DisplayName; dmp.DataSet:=dataset; if (dmp.fieldname='txtState') or (dmp.FieldName='txtOldState') then begin dmp.Calculated:=true; dmp.DisplayWidth:=255; dmp.size:=255; end; end; dataset.active:=true; finally initing:=false; end; end; procedure TSampleForm.dsSampleAfterClose( DataSet: TDataSet); var i:integer; dmp:TField; begin if not initing then begin for i:=DataSet.FieldCount-1 downto 0 do begin dmp:=pointer(DataSet.Fields.Fields[i]); DataSet.Fields.Fields[i].DataSet:=nil; freeandnil(dmp); end; DataSet.FieldDefs.Clear; end; end; procedure TSampleForm.dsSampleCalcFields( DataSet: TDataSet); var tmpdurum,tmpOldDurum:integer; begin if not initing then begin tmpDurum := dataset.FieldByName( 'state' ).AsInteger; tmpOldDurum:= dataset.FieldByName( 'oldstate' ).AsInteger; dataset.FieldByName( 'txtState' ).AsString := State2Text(tmpDurum); dataset.FieldByName( 'txtOldState' ).AsString := State2Text(tmpOldDurum); end; end; procedure TSampleForm.btnOpenClick(Sender: TObject); begin if dsSample.Active then dsSample.Close; dsSample.SQL.text:='select id,state,oldstate,"" as txtState,"" as txtOldState from states where active=1'; dsSample.Open; end; </code></pre>

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