Question

I have a 9 table db set up like this.

TableA
acct_id

TableB
tabB_id
tabA_id_fk

TableC
tabC_id
tabB_id_fk

TableD
tabD_id
tabB_id_fk

TableE
tabE_id
tabB_id_fk

I’m sure you see the pattern by now. The second table reference the first and all others reference the second. The second table (TableB) has seven tables which reference it through foreign keys. One of the tables is one-to-many with TableB, let’s say TableD. I want to delete the corresponding rows in all the tables with one query. I’ve searched for awhile and can’t find an answer. Here is the SQL statement I’m using.

DELETE FROM photos, location, contacts, messages, stats, viewed_by, ethnicity,  profile, members
USING photos INNER JOIN location 
INNER JOIN contacts 
INNER JOIN messages 
INNER JOIN stats 
INNER JOIN viewed_by 
INNER JOIN ethnicity 
INNER JOIN profile 
INNER JOIN members 
WHERE photos.profile_id_fk = profile.profile_id 
AND location.profile_id_fk = profile.profile_id 
AND stats.profile_id_fk = profile.profile_id 
AND viewed_by.profile_id_fk = profile.profile_id 
AND ethnicity.profile_id_fk = profile.profile_id 
AND profile.member_id_fk = members.member_id 
AND members.member_id=?

The query does not return any errors but it also doesn’t delete any rows. What could be the problem?

Should I just use nine seperate delete queries, one for each table?

Thanks everyone.

Answer 1

My first answer assumes InnoDB. This answer does this for MyISAM.
delete in mysql

> desc parent; desc child_1; desc child_2;
+-------+--------------+------+-----+---------+-------+
| Field | Type         | Null | Key | Default | Extra |
+-------+--------------+------+-----+---------+-------+
| id    | int(11)      | NO   | PRI | NULL    |       |
| name  | varchar(100) | YES  |     | NULL    |       |
+-------+--------------+------+-----+---------+-------+
2 rows in set (0.00 sec)

+--------------+--------------+------+-----+---------+-------+
| Field        | Type         | Null | Key | Default | Extra |
+--------------+--------------+------+-----+---------+-------+
| id           | int(11)      | NO   | PRI | NULL    |       |
| parent_id_fk | int(11)      | YES  |     | NULL    |       |
| name         | varchar(100) | YES  |     | NULL    |       |
+--------------+--------------+------+-----+---------+-------+
3 rows in set (0.00 sec)

+--------------+--------------+------+-----+---------+-------+
| Field        | Type         | Null | Key | Default | Extra |
+--------------+--------------+------+-----+---------+-------+
| id           | int(11)      | NO   | PRI | NULL    |       |
| parent_id_fk | int(11)      | YES  |     | NULL    |       |
| name         | varchar(100) | YES  |     | NULL    |       |
+--------------+--------------+------+-----+---------+-------+
3 rows in set (0.01 sec)

> select * from parent; select * from child_1; select * from child_2;
+----+------------+
| id | name       |
+----+------------+
|  1 | Andreas    |
|  2 | Wederbrand |
+----+------------+
2 rows in set (0.00 sec)

+----+--------------+-----------+
| id | parent_id_fk | name      |
+----+--------------+-----------+
|  1 |            1 | Child 1 1 |
|  2 |            1 | Child 1 2 |
|  3 |            2 | Child 2 1 |
|  4 |            2 | Child 2 2 |
+----+--------------+-----------+
4 rows in set (0.00 sec)

+----+--------------+-----------+
| id | parent_id_fk | name      |
+----+--------------+-----------+
|  1 |            1 | Child 1 1 |
|  2 |            1 | Child 1 2 |
|  3 |            2 | Child 2 1 |
|  4 |            2 | Child 2 2 |
+----+--------------+-----------+
4 rows in set (0.00 sec)

> delete p, c1, c2 from parent p, child_1 c1, child_2 c2 where p.id = c1.parent_id_fk and p.id = c2.parent_id_fk and p.id = 2;
Query OK, 5 rows affected (0.33 sec)

Your query could be correct, I don’t have your tables, but test with

DELETE photos, location, contacts, messages, stats, viewed_by, ethnicity,  profile, members
FROM photos 
INNER JOIN location 
INNER JOIN contacts 
INNER JOIN messages 
INNER JOIN stats 
INNER JOIN viewed_by 
INNER JOIN ethnicity 
INNER JOIN profile 
INNER JOIN members 
WHERE photos.profile_id_fk = profile.profile_id 
AND location.profile_id_fk = profile.profile_id 
AND stats.profile_id_fk = profile.profile_id 
AND viewed_by.profile_id_fk = profile.profile_id 
AND ethnicity.profile_id_fk = profile.profile_id 
AND profile.member_id_fk = members.member_id 
AND members.member_id=?