Re: REFERENCES constraint
От | Grigoriy G. Vovk |
---|---|
Тема | Re: REFERENCES constraint |
Дата | |
Msg-id | 20010808202427.Q574-100000@callisto.internal.linustech.com.cy обсуждение исходный текст |
Ответ на | REFERENCES constraint (Cedar Cox <cedarc@visionforisrael.com>) |
Список | pgsql-sql |
As for me it is looking as not good normalized structure. After normalization should not be any questions, I think... Aug 8, 19:02 +0300, Cedar Cox wrote: > > Two questions (maybe they are silly..) > > 1. Can a column reference more than one table? (This assumes you use a > single sequence to generate the IDs for both "tbla" and "tblb". I guess > you would also have the problem of enforcing a unique index. Say what?! > A unique index across multiple tables.. absurd :) eg.. > > CREATE TABLE blah ( > id int4, > f_id int4 REFERENCES tbla (id) REFERENCES tblb (id) > ) > > 2. Can a column reference another column in the same table? eg.. > > CREATE TABLE bloo ( > id int4, > p_id int4 REFERENCES bloo (id) > -- or > --p_id int4 REFERENCES (id) > ) > > I'm guessing the answer is no, in which case I have to fall back to > writing custom PL/ functions and triggers. Just thought I'd ask anyway. > It would be nice if it were this easy though... > > -Cedar > p.s. please CC my on this thread.. I'm on vacation (on this list) :0 > > > ---------------------------(end of broadcast)--------------------------- > TIP 1: subscribe and unsubscribe commands go to majordomo@postgresql.org > my best regards, ---------------- Grigoriy G. Vovk
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