On Thu, Apr 18, 2019 at 1:15 PM Pól Ua Laoínecháin <linehanp@tcd.ie> wrote:
SELECT (user_id, article_id)::text, count(*) FROM test_article WHERE 1 = (SELECT 1) GROUP BY user_id, article_id HAVING count(*) > 1
But what I really want (what I really, really want - apologies to the Spice Girls) to know is, is there a query which will run and stop on the first match? Using ANY, ALL or EXISTS or some construct like that?
Create a unique index over user_id, article_id on the test_article table. The system will never allow a duplicate to be inserted in the first place.
That said your query is overly complicated...
SELECT user_id, article_id
FROM test_article
GROUP BY user_id, article_id
HAVING count(*) > 1
A where clause is optional and the composite and count in the select list aren't really needed unless you have some other unstated requirement for them.
