Re: SQL Question
От | Mo Holkar |
---|---|
Тема | Re: SQL Question |
Дата | |
Msg-id | 5.1.0.14.2.20011111120039.009fda50@pop.ntlworld.com обсуждение исходный текст |
Ответ на | SQL Question (Brian <Brrrian@Excite.com>) |
Ответы |
XML & Postgresql
|
Список | pgsql-novice |
At 18:26 10/11/01, you wrote: >A SQL Question... > >Bear with me... I'm kinda new here. > >I am trying to query table1, selecting records that do NOT have a relation >in a subset from table3 that is related to table2. > > >Example: > >table1(Trick table) > 1_id,trickName,trickDescription > >table2(Magician table) > 2_id,lastName,firstName > >table3(Trick-Magician-Knows table) > 2_id,1_id > >if I choose some magician I want a list of tricks he/she DOES-NOT know. Interesting question! I'm no SQL expert either... I would use something like: SELECT one_id FROM table1 EXCEPT SELECT one_id FROM table3 WHERE table3.two_id = table2.two_id AND table2.lastName = '<name of magician to test for>'; which does generate the correct results, but there are probably more elegant ways of doing it. best, Mo Mo Holkar Digital Mind Games -- log on to take over mo.holkar@digitalmindgames.com http://www.digitalmindgames.com
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