Re: Database design?
От | Aasmund Midttun Godal |
---|---|
Тема | Re: Database design? |
Дата | |
Msg-id | 20011023164200.22669.qmail@ns.krot.org обсуждение исходный текст |
Ответ на | Re: Database design? ("Ernesto Baschny" <ernst@baschny.de>) |
Список | pgsql-general |
You can insert values into this structure which have the same id... INSERT INTO books (id) values (1); INSERT INTO cds (id) values (1); Which may be a problem (which may fix :) Regards, Aasmund. On Tue, 23 Oct 2001 16:43:29 +0200, "Ernesto Baschny" <ernst@baschny.de> wrote: > On 23 Oct 2001 at 9:11, Johnny Jørgensen wrote: > > rdbm > book,author,country,cd,publisher) > therefore can't > description. Thing > different > i've figured > tables as > relation. > reference more > e-book, a > them. > description > > Maybe you could use inherited tables to achieve that. > > CREATE TABLE items ( > id SERIAL, > description TEXT, > > PRIMARY KEY (id) > ) > > CREATE TABLE books ( > isbn VARCHAR(15), > other_field INTEGER, > ... > > ) INHERITS (items); > > CREATE TABLE cds ( > title VARCHAR(15), > ... > > ) INHERITS (items); > > With this you can define the "general" attributes in the > "items" table and more specific things in the specific tables. > > The primary key for all those tables will be kept unique > across tables, since they will all refer to the same > SEQUENCE. > > Maybe there are more elegant and correct solutions, I am > just beginning my jorney to the PgSQL world (this, for > example, couldn't be done with MySQL). > > -- > Ernesto Baschny <ernst@baschny.de> > http://www.baschny.de - PGP Key: > http://www.baschny.de/pgp.txt > Sao Paulo/Brasil - Stuttgart/Germany > Ernst@IRCnet - ICQ# 2955403 > > > ---------------------------(end of broadcast)--------------------------- > TIP 6: Have you searched our list archives? > > http://archives.postgresql.org Aasmund Midttun Godal aasmund@godal.com - http://www.godal.com/ +47 40 45 20 46
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