How to delete rows using an outer join

Question

I\'ve got a problem to delete records from a PostgreSQL table, using a LEFT JOIN.

I\'d like to delete rows I get with the following query:

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Answer 1

Still don't understand why my previous query doesn't work (if someone could explain, would be nice), but here is how I did the trick:

DELETE FROM url WHERE NOT EXISTS (SELECT * FROM link_type WHERE url.link_type = link_type.id );