On Wednesday 23 May 2007 18:59, you wrote: > > I don't believe this is good design. You'll have to have a trigger or > something to verify that the country_id+state_id on the city table are > exactly equal to the country_id+state_id on the state table. If you > don't, you might have something like (using US city names...) "country: > USA -> state: NY" -> "country: Zimbabwe -> state: NY -> city: New > York".
> > It isn't a problem of "any country and any state" on the city table, but > a problem of "this state inside that particular country". I'd drop the > country column. You are right, this is a bad design. The country_id on the city table has to go. ---------------------------(end of broadcast)--------------------------- TIP 6: explain analyze is your friend
