You can add calculated TField descendents to the Field list at run-time.
Your just need to call <Query>.Fields.Update and <Query>.CreateFields.
Just watch out, CreateFields is a TDataSet method and is not available
from TQuery so you need a Casting Cheat type.
--
type
TCheatDataSet = class(TDataSet);
...
procedure CreateCalculatedStringField(PFieldName: String; PQuery:
TwwQuery; PSize: Integer);
var
LCalculatedStringField: TStringField;
begin
//Create also some calculated fields
LCalculatedStringField := TStringField.Create(pQuery);
LCalculatedStringField.FieldName := PFieldName;
LCalculatedStringField.FieldKind := fkCalculated;
LCalculatedStringField.Calculated := True;
LCalculatedStringField.Size := PSize;
LcalculatedStringField.DataSet := pquery;
end;
...
<Query>.FieldDefs.Update;
TCheatDataSet(<Query>).CreateFields;
// And now use CreateCalculatedStringField to add calculated string
fields.
TTFN.
----
Struan Judd <*> EMail: [EMAIL PROTECTED]
CJN Technologies Ltd Phone: +64 (9) 415 4796
All opinions mine only Mobile: +64 (21) 685 335
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]
Sent: Friday, 22 January 1999 00:10
To: Multiple recipients of list delphi
Subject: [DUG]: Creating Fields at RunTime
How can I create a calculated field at runtime ? Using FieldDefs.Add
puts the field in fieldefs, but no where else. It is missing from
Fields property , the grid cant display it etc..
Rohit
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