Intersect im Tquery sql

[The_ New_Guy]

wens interessiert;
mein code:

Delphi-Quellcode:

  Query1.Sql.Clear;

  gl_kat := combobox2.ItemIndex; // die kombobox bei itemindex 0 liefert nichts zurück
     if gl_kat = 1 then
     query1.SQL.Add('select * from exceltabDatabase where gl <= 5');

     if gl_kat = 2 then
     query1.SQL.Add('select * from exceltabDatabase where gl between 6 and 10');

     if gl_kat = 3 then
     query1.SQL.Add('select * from exceltabDatabase where gl between 11 and 15');

     if gl_kat = 4 then
     query1.SQL.Add('select * from exceltabDatabase where gl > 15');



    if not((checkbox2.Checked = false) and (checkbox3.checked = false)) then
    begin
      if gl_kat > 0 then query1.SQL.Add('Intersect'); // intersect gibts ja nich leider.

      if checkbox2.Checked = true then
      begin
        query1.SQL.Add('Select * from exceltabdatabase where erfolg = 0');
      end;

      if checkbox3.Checked = true then
      begin
        query1.SQL.Add('Select * from exceltabdatabase where erfolg = 1');
      end;
    end;