On Wednesday, June 12, 2013 7:52:27 AM UTC-7, Charlie Clark wrote: > > Am 11.06.2013, 23:47 Uhr, schrieb Andy <[email protected] <javascript:>>: > > > I could do that, but I'd change the foreign key in favorites to point at > > group_things, since your favorite group must be a group that you're in. > > Then I'd drop the other foreign key constraint as unnecessary, since > it's > > implied by the new one, and then I'd be back at square one (needing to > > convince the ORM to understand a relation with no real foreign key). > > Ah, okay. I think I understand what I was missing initially. I've had > another go at this and it seems to work as required, even on MySQL. Not > sure how this all works with SQLAlchemy but I would expect it to be fine > with it. > > insert into favourites (thing_id, group_id) values (2, 2) > Error Code: 1062. Duplicate entry '2' for key 'PRIMARY' 0.012 sec > > insert into favourites (thing_id, group_id) values (1, 3) > Error Code: 1452. Cannot add or update a child row: a foreign key > constraint fails ("favourites"."favourites", CONSTRAINT "checker" FOREIGN > > KEY ("thing_id", "group_id") REFERENCES "groups_things" ("thing_id", > "group_id")) 0.007 sec >
It's not, at least with automatically configured relations, hence this thread. > > > Also, SERIAL? You must be using a real database engine. > > Well, er, yes. When it comes to modelling that's where you should start. > And Oracle is making progress with MySQL now that InnoDB with separate > files pro table and 5.6 even seems to have some kind of vacuuming > built-in. > I dunno. This may be the end of my (nonexistent) web developer career, but I think I will never again recommend using mysql for any purpose whatsoever (except perhaps compatibility). I've learned my lesson. Next time I'll use PostgreSQL. -- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/sqlalchemy?hl=en. For more options, visit https://groups.google.com/groups/opt_out.
