Michael Glaesemann wrote:
I'm trying to concatenate strings in variable orders using a custom
aggregate. However, I'm having a difficult time figuring out the SQL I
need to use to accomplish this. Here's a test case that shows the error
I'm getting.
select bar_id, array_accum(foo_value)
from ordered_foo
group by bar_id
order by bar_id;
bar_id | array_accum
--------+-----------------------------
1 | {delta,alpha,charlie,bravo}
2 | {C,B,A,D}
The result I'd like to see is
bar_id | array_accum
--------+-----------------------------
1 | {alpha,bravo,charlie,delta}
2 | {A,B,C,D}
Just use a subselect -- you're looking for this, correct?
regression=# select bar_id, array_accum(foo_value) from (select * from
ordered_foo order by foo_pos) as ss group by bar_id order by bar_id;
bar_id | array_accum
--------+-----------------------------
1 | {alpha,bravo,charlie,delta}
2 | {A,B,C,D}
(2 rows)
HTH,
Joe
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