CODEWITHSUNDEEP
delphifiredacdelphi-10.2-tokyotdatasetprovider
Jan Doggen
Jan Doggen

Reputation: 9096

Exception caused by TDataSetProvider poUseQuoteChar and lowercase table names does not surface

The default TDataSetProvider.Options.poUseQuoteChar is true.

I was (again) bitten by this when my SQL statement used a lower case table name and my TClientDataSet.ApplyUpdates(0) did not do any updates without raising an exception.

In DataSnap.Provider the code in function TCustomResolver.InternalUpdateRecord(Tree: TUpdateTree): Boolean; traps the exception:

except
  if ExceptObject is Exception then
  begin
    E := Exception(AcquireExceptionObject);
    PrevErr.Free;
    PrevErr := Err;
    Err := (Tree.Source as IProviderSupportNG).PSGetUpdateException(E, PrevErr);
    if HandleUpdateError(Tree, Err, FMaxErrors, FErrorCount) then
    begin
      Tree.Delta.UseCurValues := True;
      Continue;
    end else
      break;
  end else
    raise;
end;

and I see that E.Message is

[FireDAC][Phys][FB]Dynamic SQL Error'#$D#$A'SQL error code = -204'#$D#$A'Table unknown'#$D#$A'tt_calendar'#$D#$A'At line 1, column 8

I have no ReconcileErrorHandler, and in the above code HandleUpdateError returns false, but for some reason the exception does not surface.

My setup is:

New events created in DevExpress TcxSchedulerStorage, connected to TDataSource -> TClientDataSet -> TDataSetProvider -> TFDQuery -> TFDConnection, in this case to a Firebird database. Everything default settings, simple select * from tablename in TFDQuery.SQL.Text,
using Delphi Tokyo 10.2.3.

Is there a single setting that I can change that would force the exception visible and that solves this once and for all (for any database type)?
I'm even willing to patch a Delphi file.

I have now 'solved' this with runtime code:

procedure TDMTT.DataModuleCreate(Sender: TObject);
var i: integer;
begin
  for i := 0 to ComponentCount-1 do
    if Components[i] is TDataSetProvider then
       (Components[i] as TDataSetProvider).Options := (Components[i] as TDataSetProvider).Options - [poUseQuoteChar];
end;

but would prefer not having to think of this every time.

Upvotes: 0

Views: 360

Answers (1)

Jan Doggen
Jan Doggen

Reputation: 9096

As Sertac Akyuz suggested, modifying the TDataSetProvider constructor is one option. The drawback is that you are patching Delphi code, but I'm fine with that.

In Datasnap.Provider, add the indicated line:

constructor TDataSetProvider.Create(AOwner: TComponent);
begin
  inherited Create(AOwner);
  FResolveToDataSet := False;
  UpdateMode := upWhereAll;
  FDSWriter := nil;
  FConstraints := True;
  FRecordsSent := 0;
  Options := Options - [poUseQuoteChar];  // Line added
end;

Upvotes: 1

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