Question

Here is my question :
I have a database (mysql) like this :

id0
id1
id2

And i would like to delete the lines who have the couple (id1,id2) in common to keep only one.
Example :
1/1/1
2/1/2
3/1/2 <= Delete
4/2/1
5/2/3
6/2/3 <= Delete

I hope this is clear enough for you to help me 🙂
Thanks

Answer 1

Assuming id0 is unique (thus the MIN(id0) for all equivalent tuples (id1, id2) is the only one to be kept):

DELETE
FROM tbl
WHERE id0 NOT IN (
    SELECT MIN(id0)
    FROM tbl
    GROUP BY id1, id2
)