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" for read only" clause appended for safety when UseDeclareFetch=1 breaks some sql statements with trailing semicolons - Mailing list pgsql-odbc

From Jack Wilson
Subject " for read only" clause appended for safety when UseDeclareFetch=1 breaks some sql statements with trailing semicolons
Date
Msg-id OF0B65CC2A.83351659-ON85257403.005E4A54-85257403.005F978C@digitalav.com
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Responses Re: " for read only" clause appended for safety when UseDeclareFetch=1 breaks some sql statements with trailing semicolons  (Hiroshi Inoue <inoue@tpf.co.jp>)
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I've found the change made in version psqlodbc 8.2.0501 and later (reference: http://archives.postgresql.org/pgsql-committers/2007-10/msg00420.php)

4. Be more careful about <for locking clause> in UseDeclareFetch mode.
  Add missing? "for read only" clause for read only queries for 8.3
  or later servers for safety.

Here is a cvs link to the actual code change:
http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/psqlodbc/psqlodbc/convert.c.diff?r1=1.163&r2=1.164

This change breaks existing code that sends a single sql statement with a trailing semicolon. What happens is the odbc driver sees UseDeclareFetch=1 and for sql statements appends " for read only" at the end of the statement. This is fine except for the situation where the statement has a trailing semicolon. In that case the statement ends up being (say) "select blah blah; for read only", which gives a syntax error like:

ERROR: syntax error at or near "for"
SQL state: 42601

Setting UseDeclareFetch=0 fixes the problem, or using psqlodbc 8.2.0500 or earlier, or using PostgreSQL 8.2.6--any one of these prevents the " for read only" from being appended to the end of the sql statement.

The quick fix was to remove the trailing semicolons in my code, but a better fix would be to make the parser smart enough to put the " for read only" clause in front of an existing semicolon, not after it.

Thanks...jack
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