BUG #16507: RTRIM function doesnt behave as expected for certain scenario

Started by PG Bug reporting formalmost 6 years ago2 messagesbugs
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#1PG Bug reporting form
noreply@postgresql.org

The following bug has been logged on the website:

Bug reference: 16507
Logged by: Chetan Burande
Email address: chetan.burande7@gmail.com
PostgreSQL version: Unsupported/Unknown
Operating system: Linux
Description:

Hi Team,

I am trying to use RTIM function on a String (Column data) to remove some
character/string from the right end.

Example -
select column_name, RTRIM(column_name, '-1') from table_name;
column_name | rtrim
-----------------------------------------+---------------------------------------
test-2020_03_01-2020_03_31-1 | test-2020_03_01-2020_03_3
test-2019_02_01-2019_02_28-1 | test-2019_02_01-2019_02_28
test-2019_04_01-2019_04_30-1 | test-2019_04_01-2019_04_30

In case of the first string, RTRIM is removing "1-1" instead of "-1".
I expect it to remove "-1" as it did in other strings.

Please let me know if you need any further information.

Thanks,
Chetan

#2Tom Lane
tgl@sss.pgh.pa.us
In reply to: PG Bug reporting form (#1)
Re: BUG #16507: RTRIM function doesnt behave as expected for certain scenario

PG Bug reporting form <noreply@postgresql.org> writes:

I am trying to use RTIM function on a String (Column data) to remove some
character/string from the right end.
Example -
select column_name, RTRIM(column_name, '-1') from table_name;
In case of the first string, RTRIM is removing "1-1" instead of "-1".
I expect it to remove "-1" as it did in other strings.

Your expectation is wrong, per the function's documentation:

Removes the longest string containing only characters in
'characters' (a space by default) from the end of 'string'.

The example is pretty explicit about this, too:

rtrim('testxxzx', 'xyz') → test

You could do what you want with regexp_replace() or the pattern-matching
variant of substring().

regards, tom lane