Hi all,
A little question about grouping by a computed column alias where other
columns with same name exists.
Take look at this query (don't take care about, it was created as a test
to explain my question).
select case when (second_table.c1 = 'X') then '1' else '2' end as c1,
first_table.c2
from (
select 'A'::text as c1, 'B'::text as c2
) first_table
inner join (
select 'X'::text as c1
union
select 'W'::text as c1
union
select 'X'::text as c1
) second_table on (true)
group by c1, first_table.c2
I have a computed coulmn alias in select called c1 (select case when
(second_table.c1 = 'X') then '1' else '2' end as c1)
I want to group by that alias c1 (group by c1)
BUT first_table has a c1 column and second_table has a c1 column too!
If i run the query it returns "ERROR: column reference "c1" is ambiguous"
Someone knows a way to solve this?
Not replacing grou by alias with its case and without changing column
names, oblivious.
In other dbs (like firebird) main (computed ) select column alias name
takes precedence in group by clause. So if i group by c1 that means the
computed (case when.... ) c1 in that case.
Best regards,
Agharta
