BUG #17671: Query returns unexpected result
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
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:
Show quoted text
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
On Mon, 31 Oct 2022 at 13:15, 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?
The UNION eliminates duplicate rows from its result, in the same way as
DISTINCT [1]https://www.postgresql.org/docs/current/queries-union.html.
[1]: https://www.postgresql.org/docs/current/queries-union.html
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