Question

I have Table A with the following values:

    
+------+------+
| ID1  | ID2  |
+------+------+
| 1689 | 1709 |
| 1709 | 1689 |
| 1782 | 1709 |
| 1911 | 1247 |
| 1247 | 1468 |
| 1641 | 1468 |
| 1316 | 1304 |
| 1501 | 1934 |
| 1934 | 1501 |
| 1025 | 1101 |
+------+------+

and another relation (Table B) with the following values:

+------+------+
| ID1  | ID2  |
+------+------+
| 1641 | 1468 |
| 1911 | 1247 |
+------+------+

I would like to delete all rows in Table A that appear in Table B (an exact match on ID1 and ID2). Seems simple in theory but I’m having no joy with the EXISTS statement or other approaches. I’m using SQLite.

Any suggestions greatly appreciated.

Answer 1

How about: (not too sure whether this works in SQLite)

DELETE FROM TableA
WHERE EXISTS (SELECT *
              FROM TableB
              WHERE TableB.ID1 = TableA.ID1
                AND TableB.ID2 = TableA.ID2)