Re: SQL question

From: Maxim Demenko <mdemenko_at_arcor.de>
Date: Wed, 19 Oct 2005 19:05:55 +0200
Message-ID: <43567d18$0$6772$9b4e6d93@newsread4.arcor-online.net>

Michel Cadot schrieb:
> Maybe it's a silly question but i can't find the answer.
> Why can't Oracle resolve "a.dummy" in the following (meaningless) queries (8.1.7.4 & 9.2.0.6)?
>
> SQL> select ( select dummy
> 2 from ( select dummy
> 3 from dual b
> 4 where b.dummy = a.dummy
> 5 )
> 6 ) dummy
> 7 from dual a
> 8 /
> where b.dummy = a.dummy
> *
> ERROR at line 4:
> ORA-00904: "A"."DUMMY": invalid identifier
>
>
> SQL> select dummy
> 2 from dual a
> 3 where exists ( select 1
> 4 from ( select dummy
> 5 from dual b
> 6 where b.dummy = a.dummy
> 7 )
> 8 )
> 9 /
> where b.dummy = a.dummy
> *
> ERROR at line 6:
> ORA-00904: "A"."DUMMY": invalid identifier
>
> Regards
> Michel Cadot
>
>

A quote from
http://asktom.oracle.com/pls/ask/f?p=4950:8:11867905451620403095::NO::F4950_P8_DISPLAYID,F4950_P8_CRITERIA:1197999096334

the correlation name B can only go one level down. the correlated subquery may
ONLY reference its parent query.

Best regards

Maxim Received on Wed Oct 19 2005 - 12:05:55 CDT