Fórum Como cancelar uma gravação através o evendo OnBeforePost. #209263

procedure TForm1.IBTable1BeforePost(DataSet: TDataSet);
begin
  if DataSet.State <> dsInsert then
     Exit;
  with TIBQuery.Create(nil) do
    try
      Database := (DataSet as TIBTable).Database;
      Transaction := (DataSet as TIBTable).Transaction;
      SQL.Clear;
      SQL.Add(´SELECT SOCIO_NOME´);
      SQL.Add(´FROM NomeTabela´);
      SQL.Add(´WHERE SOCIO_NOME = ´ + QuotedStr(DataSet.Fields[0].AsString));
      Open;
      try
        if not IsEmpty then
           begin
             FormSocioIncluir.edbNome.SetFocus;
             raise EDatabaseError.Create(´Este cliente já existe!.´);
           end;
      finally
        Close;
      end;
    finally
      Free;
    end;
end;

  Query.Params[0].Value:= UPPERCASE(FormSocioIncluir.eDBNome.text);
  Query.Open;
  if Query.RecordCount > 0 then
  begin
    ShowMessage(´Registro já existe.´);
    Query.Close;
    Abort;
  end;
  Query.Close;