Re: BUG #17671: Query returns unexpected result - Mailing list pgsql-bugs

From Kieran McCusker
Subject Re: BUG #17671: Query returns unexpected result
Date
Msg-id CAGgUQ6H2N7smAFE5=T8gaEjeggDrYHMTtRmWtAOwhrhYGkE+5w@mail.gmail.com
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In response to BUG #17671: Query returns unexpected result  (PG Bug reporting form <noreply@postgresql.org>)
List pgsql-bugs
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

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