Question

Here’s the situation:

• I have a main admin whose id, in the table person is 478.
• this admin is supposed to handle partners, in the table partners.
• there’s a table that “joins” them: person_partners.

Sometimes, some people add new partners, and I’d like to run a query that:

• either:
  • remove all links between this admin and partners, some kind of DELETE * FROM person_partners where id_person=478
  • re-insert all links between this admin and partners (= new partners will be inserted too), some kind of INSERT INTO person_partners (id_person,id_partner) VALUES (478, SELECT id FROM partners) (but this query give me this error: ERROR 1242 (21000): Subquery returns more than 1 row)
• or simply insert all partners that are not yet in person_partners with id_person=478

Any idea?

Answer 1

Like BugFinder said, “You seem to have your own answers in the question”

To fix the ERROR 1242 you have to write it like this:

INSERT INTO person_partners (id_person,id_partner) 
SELECT '478', id FROM partners;

Alternatively to “simply insert all partners that are not yet in person_partners with id_person=478” you can

INSERT IGNORE INTO person_partners (id_person,id_partner) 
SELECT '478', id FROM partners;

Read more about it here.