General Bug Report: empty SELECT WHEREs return error

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                        POSTGRESQL BUG REPORT TEMPLATE
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Your name               : Austin Schutz
Your email address      : tex@habit.com

Category                : runtime: back-end: SQL
Severity                : serious

Summary: empty SELECT WHEREs return error

System Configuration
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  Operating System   : SunOS 5.6

  PostgreSQL version : 6.0

  Compiler used      : gcc 2.8.1

Hardware:
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SunOS pita 5.6 Generic_105181-09 sun4u sparc SUNW,Ultra-1

Versions of other tools:
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Problem Description:
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select * from foo where bar = "baz"
produces "ERROR:  attribute 'hna' not found"
if there is no row with bar == "baz".
Rather than errorring an empty set should be returned.
This is important for cross-db-portable applications
which need to know whether a legitimate query returns
no rows vs. a 'bad' query.
    It would be possible to test the error response for
being the specific 'attribute not found' error, but this is
extremely un-portable behavior (code would only work on
postgres) and further would mask cases where column bar
doesn't exist and the 'attribute not found' error is
correct.

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Test Case:
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create table foo (bar char(1));
select * from foo where ( bar = "baz" );
ERROR:  attribute 'baz' not found


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Solution:
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