Re: [GENERAL] why isn't this subquery wrong?

[David G. Johnston]

On Thu, Apr 20, 2017 at 3:17 PM, jonathan vanasco <postg...@2xlp.com> wrote:

>
> SELECT foo_id
> FROM example_a__data
> WHERE foo_id IN (SELECT bar_id FROM example_a__rollup)
> ;
>
>
>
​Or write it the idiomatic way (i.e., as a proper semi-join):

​SELECT foo_id
FROM example_a__data
WHERE EXISTS (SELECT 1
                                 FROM example_a__rollup
                              WHERE example_a__rollup.bar_id =
example_a__data.foo_id)

IME its harder to forget the table prefix when using this form.

David J.