Re: Array values and foreign keys
От | Pierre-Frédéric Caillaud |
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Тема | Re: Array values and foreign keys |
Дата | |
Msg-id | opsgjddwmocq72hf@musicbox обсуждение исходный текст |
Ответ на | Array values and foreign keys (Daniel Savard <dsavard@cids.ca>) |
Ответы |
Re: Array values and foreign keys
Re: Array values and foreign keys |
Список | pgsql-general |
You can't express it directly with a CHECK constraint but you can do this : - add CHECK( test_array( yourcolumn )) in your table definition - create function test_array which takes an array and looks if all its elements are in your table T2, I do something like comparing the length of the array to SELECT count(1) FROM T2 WHERE key IN array You can do it other ways but you'll have to use a function. On Wed, 27 Oct 2004 10:19:02 -0400, Daniel Savard <dsavard@cids.ca> wrote: > Is there a way to define a foreign key for the values of an array? > > For example, if table T1 is having a colum A which is defined as > integer[] can I define a foreign key in order to force each value to be > a pointer (index) to a row in a table T2? > > If yes, how? Is there any shortcomings to this approach? > > Thanks, > > Daniel Savard > > --- > Daniel Savard > dsavard@cids.ca > > ---------------------------(end of broadcast)--------------------------- > TIP 1: subscribe and unsubscribe commands go to majordomo@postgresql.org >
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