Good morning,
Just notice one small thing, and need your information about select
select col1, col2
from table1
left join table2
using (col1, col2)
;
This query never complain about ambiguous columns of col1 and col2 in
the select part.
My guess is:
(1) col1, col2 always return table1.col1, table1.col2
(2) because using (col1, col2)
that's why, table name is not necessary in select part
Am I wrong? Please advise?
Thank you!