Re: Bug in sub-query
Tom Lane <tgl@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
To: Veeranjaneya Vara Prasad Peddireddy <varaprasad.peddireddy@valuelabs.com>
Cc: "pgsql-bugs@lists.postgresql.org" <pgsql-bugs@lists.postgresql.org>
Date: 2025-12-12T15:26:12Z
Lists: pgsql-bugs
Veeranjaneya Vara Prasad Peddireddy <varaprasad.peddireddy@valuelabs.com> writes: > --query 2: > select * from admin.emp where location_id_location=108 > and sno in (select dim_id from admin.emp_dimension where location_id_location=108) > --Note2: it returned two records and no error given. > --But if you observe above query 2; the sub-query is not correct. In sub-query; location_id_location is not present in table admin.emp_dimension. But same sub-query failed in query 1. This is not a bug, it is behavior required by the SQL standard. If location_id_location is not found among the columns available from the sub-query's FROM clause, it will be treated as an "outer reference" to columns available from the outer query. The usual way to avoid falling into this trap is to always relation-qualify column references, especially in sub-queries. regards, tom lane