I have some troubles with deleting partial duplicate rows
The structure is like this:
+-----+--------+--+-----------+--+------+
| id | userid | | location | | week |
+-----+--------+--+-----------+--+------+
| 1 | 001 | | amsterdam | | 11 |
| 2 | 001 | | amsterdam | | 23 |
| 3 | 002 | | berlin | | 28 |
| 4 | 002 | | berlin | | 22 |
| 5 | 003 | | paris | | 19 |
| 6 | 003 | | paris | | 35 |
+-----+--------+--+-----------+--+------+
I only need to keep one row from each userid, it doesn't matter which week number it has.
Thanks, Maxcim
This should work across most databases:
DELETE
FROM yourTable
WHERE id <> (SELECT MIN(id)
FROM yourTable t
WHERE t.userid = userid)
This query would delete from each userid
group all records except for the record having the lowest id
for that group. I assume that id
is a unique column.