Re: partial unique constraint

On 06/04/2004 15:29 Robert Treat wrote:
> Trying to come up with the proper syntax to meet the following criteria:
> 
> create table foo (bar integer, baz boolean UNIQUE (bar, baz = true));
> 
> note the above syntax is not correct, but should demonstrate what i'm
> trying to do; I want to add a unique constraint such that we only allow
> one case of bar and baz = true...  i can have unlimited bar and baz =
> false, and there can be multiple bar and baz = true if the bars are
> different...  did some doc reading and mail list searching but a valid
> syntax for this seems to be escaping me...
> 
> btw I'm pretty sure I could do this with an external trigger, but am
> wondering about a constraint oriented approach

What about

create table foo (bar integer, baz boolean);

create unique index foo_bar_baz on foo(bar, baz) where baz = true;

-- 
Paul Thomas
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