Re: BUG #17671: Query returns unexpected result

It's not a bug. Union removes duplicates. Use union all.

Kieran

On Mon, 31 Oct 2022, 10:03 PG Bug reporting form, <noreply@postgresql.org>
wrote:

> The following bug has been logged on the website:
>
> Bug reference:      17671
> Logged by:          Nikola Mirkov
> Email address:      niko@aku.mx
> PostgreSQL version: 12.12
> Operating system:   Ubuntu 12.12-0ubuntu0.20.
> Description:
>
> Hey guys,
> When I run the following query:
> SELECT foo, bar
> FROM table1
> WHERE fk_id = 637
> AND utc > '2022-10-16'
> UNION
> SELECT foo, bar
> FROM table2
> WHERE fk_id = 637
> AND utc > '2022-10-16'
>
> I'm getting only one row per table. If I add the column "utc" to the list
> in
> SELECT, I get the expected result.
>
> Why is this happening?
>
> Thank you so much!
> Niko
>
>