PostgreSQL Bugs

Collected from the PG bugs email list.

Bug ID16107
PG Version11.5
OSLinux
Opened2019-11-11 22:34:28+00
Reported byAndrew Wheelwright
StatusNew

Body of first available message related to this bug follows.

The following bug has been logged on the website:

Bug reference:      16107
Logged by:          Andrew Wheelwright
Email address:      (redacted)
PostgreSQL version: 11.5
Operating system:   Linux
Description:        

I ran into a scenario where I found results getting dropped from string
aggregation.  Here's a basic example which reproduces the problem on three
different servers running PostgreSQL 9.6.6, 10.6, and 11.5, respectively.  I
don't have an instance running version 12.

with dataset as (
	select 'One' "Label", 1 "ID"
	union
	select 'Two' "Label", 2 "ID"
	union
	select 'Three' "Label", 3 "ID"
)
select
	string_agg(', ', "Label" order by "ID") "String Aggregated Labels",
	array_agg("Label" order by "ID") "Array Aggregated Labels"
from
	dataset
;

Which renders the following result:
String Aggregated Labels: `, Two, Three, `
Array Aggregated Labels: `{One,Two,Three}`

The value "One" is missing from the string aggregate result and there is a
dangling separator on both ends of the string.

Messages

DateAuthorSubject
2019-11-11 22:34:28+00PG Bug reporting formBUG #16107: string_agg looses first item
2019-11-11 22:47:39+00Tom LaneRe: BUG #16107: string_agg looses first item