Re: Default value if query returns 0 rows?

[snip]
> Another way is a subselect:
>
>     select coalesce((select id from map where name = 'foo'), -1);
Then why not:

select coalesce((select id from map where name = 'foo' limit 1), -1);

This should work even if there are more rows with foo.

>
> but this one will actively blow up if there are multiple 'foo' rows,
> so it doesn't solve that problem either.
>
>             regards, tom lane
>