Question

I am trying to load database data by using dbplannercalender1.

procedure TForm1.DBPlannerCalendar1DaySelect(Sender: TObject;
  SelDate: TDateTime);
begin
with absQuery2 do
begin
  absQuery2.Close;
  absQuery2.sql.Clear;
  ABSQuery2.SQL.Text:='select * from log where date = :a1';
  ABSQUERY2.PARAMS.ParamByName('a1').value:= DBPlannerCalendar1.Date;
  ABSQuery2.ExecSQL;
end;
end;

I get the error “date string expected”YYYY-MM-DD”,but “=”found at line 1…”
What am I doing wrong ?

Answer 1

Use AsDateTime instead of Value, to let the driver convert it to the proper format:

AbsQuery2.Params.ParamByName('a1').AsDateTime := DBPlannerCalendar1.Date;

If Absolute doens’t support AsDateTime for some reason, format the date yourself:

AbsQuery2.Params.ParamByName('a1').Value := 
    FormatDateTime('yyyy-mm-dd`, DBPlannerCalendar1.Date);

The first method is the best choice, because it works more portably between database engines (it works for all of them, because the driverr does the formatting into the proper arrangement for dates). Using the second means that if the DB expects something different than YYYY-MM-DD, you have to change the code everywhere that uses dates.