Hi folks,

I need to do a modification on a  readonly TEDBQuery before converting to JSON string (no need to affect the database) and I really don't want to go with the overhead of using TClientDataset.

Here's the code

       sqlGetMovs.First;
       while not sqlGetMovs.Eof do
       begin
         sqlGetMovs.Edit; <--- Readonly Error
         saldo := saldo + (sqlGetMovs.FieldByName('ingresos').AsFloat -          sqlGetMovs.FieldByName('egresos').AsFloat);
         sqlGetMovs.FieldByName('saldo').Value := saldo;
         sqlGetMovs.Post;
         sqlGetMovs.Next;
       end;
       JSONRaw := DataSetToJSON(sqlGetMovs);

Is there any property or setting that could help avoid the read only validation?

Regards,
Mario

> I need to do a modification on a  readonly TEDBQuery before converting to JSON string (no need to affect the database) and I really don't want to go with the overhead of using TClientDataset.

I don't know of anything direct that you can change in EDB to allow for this.  In my app, I use a TFDMemTable to get thing local when EDB can't.  I have a global function that I can call, which makes it really easy to grab any query results with a single function call just by passing the EDB object:

function GetFDMemTable(DataSet: TDataSet; CachedUpdates: Boolean): TFDMemTable;
begin
 Result := TFDMemTable.Create(nil);
 Result.CachedUpdates := CachedUpdates; //indicate if you want to keep track of changes
 Result.CopyDataSet(DataSet, [coStructure, coRestart, coAppend]);
 if CachedUpdates then Result.MergeChangeLog;
end;

If you have the DevExpress components, you can also use the TdxMemData class, or any other in memory dataset that you might have installed in your environment.

Thank you very much Terry, I would look into it.

Mario


I must be missing something here, or being very thick, why not just include that in the sql that generates sqlGetMovs?

Roy Lambert

Hi Roy,

Yes, the field is include in the query, but I need to updated with some last state calculation (info not in the database). However I did solve another way. Thanks for asking.

Regards,
Mario