In article <b4dtl8$1ejl$1(at)news(dot)hub(dot)org>, Björn Lundin wrote:
> Aaron Chu wrote:
>
>> Hi,
>>
>> I have a table which has a column of surnames (string) and I would like
>> to know how can I retrieve (SELECT) all the repeated surnames, i.e.
>> more than one person who has the same surname.
>
> select surname, count('a') from table
> group by surname
> having count('a') > 1
> order by surname
>
SELECT DISTINCT surname
FROM table t1, table t2
WHERE t1.surname = t2.surname
AND t1.oid != t2.oid
ORDER BY surname;