Why *no* ambig·uous complain in select part? - Mailing list pgsql-sql

From Emi Lu
Subject Why *no* ambig·uous complain in select part?
Date
Msg-id 48AF1D9E.4020703@encs.concordia.ca
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Responses RE: [SQL] Why *no* ambig.uous complain in select part?
Re: Why *no* ambig·uous complain in select part?
List pgsql-sql
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!





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