Re: Array values and foreign keys

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(at)cids(dot)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(at)cids(dot)ca
>
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