Re: Select in From clause
От | Alvaro Herrera |
---|---|
Тема | Re: Select in From clause |
Дата | |
Msg-id | 20071109183559.GA7161@alvh.no-ip.org обсуждение исходный текст |
Ответ на | Select in From clause ("Ray Madigan" <ray@madigans.org>) |
Список | pgsql-sql |
Ray Madigan wrote: > I have never seen this done before, but it seems like it is supposed to work > from reading the manual. > > I want to be able to get a table name from another table and use it in the > from clause of a select. > > Something like > > SELECT * FROM (SELECT name FROM bar WHERE conditions) AS b WHERE b.condition > = xxx; > > which translates to something like > > SELECT * FROM Dealer AS b WHERE b.zipcode = 12345; No, that's not how it works. The stuff returned by the inner select is a set of rows which can be further operated upon by the outer select. It is not expanded into a table name. One way to construct queries is to build plpgsql functions and use EXECUTE. However, the approach you are using looks like bad practice (read: bad database design). -- Alvaro Herrera http://www.CommandPrompt.com/ The PostgreSQL Company - Command Prompt, Inc.
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