Re: Find double (not uniqe) entries in a table

[Aziz]

My previously proposed query only selects one non-distinct row because of the GROUP BY. If you want to select all non-unique rows, then the query should look like this:

SELECT id, name, city FROM a_table
WHERE name IN
(SELECT name
FROM a_table
GROUP BY name
HAVING COUNT(name) > 1)

Or perhaps so:

SELECT id, name, city FROM a_table a1
WHERE EXISTS(
SELECT name
FROM a_table a2
WHERE a2.name = a1.name
GROUP BY a2.name
HAVING COUNT(a2.name) > 1)

Hope this helps.

Regards,
Aziz