please some help

[mcaizkt2]

app_date table
+------------+----------------+----------+------------+
| patient_ID | slotNo | staff_ID | appo_date |
+------------+----------------+----------+------------+
| 100 | 1 | G1 | 2003-02-12 |
| 101 | 1 | G1 | 2003-02-14 |
| 115 | 1 | G1 | 2003-02-15 |
| 103 | 10 | G1 | 2003-02-12 |
| 107 | 2 | G1 | 2003-02-14 |
| 101 | 3 | G1 | 2003-02-12 |
| 109 | 3 | G1 | 2003-02-14 |
| 104 | 4 | G1 | 2003-02-13 |
| 105 | 5 | G1 | 2003-02-13 |
| 102 | 6 | G1 | 2003-02-12 |
| 108 | 7 | G1 | 2003-02-14 |
| 106 | 8 | G1 | 2003-02-14 |
+------------+----------------+----------+------------+

slot table
+--------+-----------+----------+----------+
| slotNo | time_from | time_to | staff_ID |
+--------+-----------+----------+----------+
| 1 | 09:00:00 | 09:30:00 | G1 |
| 2 | 09:30:00 | 10:00:00 | G1 |
| 3 | 10:00:00 | 10:30:00 | G1 |
| 4 | 10:30:00 | 11:00:00 | G1 |
| 5 | 11:00:00 | 11:30:00 | G1 |
| 6 | 11:30:00 | 12:00:00 | G1 |
| 7 | 12:00:00 | 12:30:00 | G1 |
| 8 | 12:30:00 | 01:00:00 | G1 |
| 9 | 01:00:00 | 01:30:00 | G1 |
| 10 | 01:30:00 | 02:00:00 | G1 |
+--------+-----------+----------+----------+
I am tring to show the slotNo in slots table that is not in
slotno in app_date table, for example I have wrote this query
to display the differences between to column

SELECT slotNo, time_from
FROM slots, app_date
WHERE slots.staff_ID='G1'
and appo_date='2003-02-12'
and slots.slotNo < app_date.slotNo

the result should show
2,4,5,7,8,9
please some one help me...

[Sxooter]

Easy, you can use a subselect:

select * from slots where slotno not in (select slotno from app_table);

Or, you can use an except:

select slotno from slots except select slotno from app_table;

[mcaizkt2]

sxooter;
the problem is mysql does notsupport subquery.

[Sxooter]

Originally posted by mcaizkt2
sxooter;
the problem is mysql does notsupport subquery.

You might wanna mention what database you're using next time in your title. After all, your initial question was on SQL, and every known SQL database in the universe EXCEPT MySQL has subselects. I believe the MySQL manual has a listing of ways to get around it's lack of functionality in subselects.

Aren't they (MySQL) supposed to be getting simple subselect support soon?