[drupal-devel] [bug] Forum module's use of if in Postgresql
patrickslee
drupal-devel at drupal.org
Thu May 26 20:29:43 UTC 2005
Issue status update for http://drupal.org/node/23499
Project: Drupal
Version: 4.6.0
Component: forum.module
Category: bug reports
Priority: normal
Assigned to: patrickslee
Reported by: cchamilt
Updated by: patrickslee
Status: patch
Attachment: http://drupal.org/files/issues/database.pgsql_3.patch (363 bytes)
Here you have it.
patrickslee
Previous comments:
------------------------------------------------------------------------
May 24, 2005 - 16:32 : cchamilt
Postgresql function "if" is defined to return a boolean value, yet forum
requests an integer - last_comment_uid.
user error:
query: SELECT n.nid, l.last_comment_timestamp, IF(l.last_comment_uid,
cu.name, l.last_comment_name) as last_comment_name, l.last_comment_uid
FROM node n, node_comment_statistics l /*! USE INDEX
(node_comment_timestamp) */, users cu, term_node r WHERE n.nid = r.nid
AND r.tid = 1 AND n.status = 1 AND n.type = 'forum' AND
l.last_comment_uid = cu.uid AND n.nid = l.nid ORDER BY
l.last_comment_timestamp DESC LIMIT 1 OFFSET 0 in
/var/www/hosts/www.ambigc.com/htdocs/includes/database.pgsql.inc on
line 62.
warning: pg_query() [function.pg-query]: Query failed: ERROR: function
if(integer, character varying, character varying) does not exist
HINT: No function matches the given name and argument types. You may
need to add explicit type casts. in
/var/www/hosts/www.ambigc.com/htdocs/includes/database.pgsql.inc on
line 45.
------------------------------------------------------------------------
May 25, 2005 - 10:07 : patrickslee
Attachment: http://drupal.org/files/issues/forum.module_3.patch (2.69 KB)
I have also encountered this bug and made a possible patch by replacing
IF statements to CASE.
A patch file is attached.
------------------------------------------------------------------------
May 25, 2005 - 10:28 : adrian
There is an IF function defined in the database.pgsql function. On what
page is this happening, as what might be happening is that the type
isn't being picked up correctly.
It's defined as IF(anyelement, anyelement, text) returns anyelement.
IIRC. What I have seen happen is that it wants the text field to return
integer, or vice versa.
------------------------------------------------------------------------
May 25, 2005 - 10:32 : patrickslee
I found the definition in database.pgsql. It is like this:
CREATE FUNCTION "if"(boolean, anyelement, anyelement) RETURNS
anyelement AS '
SELECT CASE WHEN $1 THEN $2 ELSE $3 END;
' LANGUAGE 'sql';
So it is actually wanting boolean.
------------------------------------------------------------------------
May 25, 2005 - 10:43 : patrickslee
So my patch will work, and we can make it easier by replacing the IF
function to:
IF(l.last_comment_uid 0 AND l.last_comment_uid NULL, cu.name,
l.last_comment_name)
BTW there is another place in forum.module use IF like this.
------------------------------------------------------------------------
May 25, 2005 - 10:45 : patrickslee
Oops... my <>s are stolen.
IF(l.last_comment_uid <> 0 AND l.last_comment_uid <> NULL, cu.name,
l.last_comment_name)
------------------------------------------------------------------------
May 25, 2005 - 17:20 : cchamilt
Yes that line works great.
Thanks for your help!
------------------------------------------------------------------------
May 25, 2005 - 17:52 : patrickslee
This patch shows another problem.
The last post user will always show "Anonymous" or whatever you
defined.
Looking for solution...
------------------------------------------------------------------------
May 25, 2005 - 18:00 : patrickslee
Use this line instead:
IF(l.last_comment_uid <> 0 AND l.last_comment_uid <> NULL, cu.name,
l.last_comment_name)
Don't forget there are two places in forum.module need to be changed.
------------------------------------------------------------------------
May 25, 2005 - 18:10 : patrickslee
Oh what have I done! I changed nothing!
IF(l.last_comment_uid <> 0 AND l.last_comment_uid IS NOT NULL, cu.name,
l.last_comment_name)
------------------------------------------------------------------------
May 25, 2005 - 22:12 : adrian
perhaps we could also just add more wrapper functions for the specific
types ?
create or replace function IF (integer, anyelement, anyelement) returns
anyelement as '
SELECT if (($1 0) AND NOT nullvalue($1), $2, $3);
' LANGUAGE 'sql';
Or something.
------------------------------------------------------------------------
May 25, 2005 - 22:41 : plj
'' was missing. So what adrian actually means is this:
CREATE OR REPLACE FUNCTION IF (integer, anyelement, anyelement) RETURNS
anyelement AS '
SELECT if (($1 <> 0) AND NOT nullvalue($1), $2, $3);
' LANGUAGE 'sql';
I applied that and now forums work -- no module patches. PostgreSQL
7.4.7.
------------------------------------------------------------------------
May 25, 2005 - 22:45 : plj
Sheesh. I meant that '<>' was missing. Gotta learn to use that preview
button...
------------------------------------------------------------------------
May 26, 2005 - 09:53 : patrickslee
Is nullvalue() a function? I cannot find it in neither postgres manual
nor mysql manual.
Use "IS NOT NULL" would be better as it is more standard-compatible.
SO we have this:
CREATE OR REPLACE FUNCTION IF (integer, anyelement, anyelement) RETURNS
anyelement AS '
SELECT IF(($1 <> 0) AND $1 IS NOT NULL, $2, $3);
' LANGUAGE 'sql';
Looks we have a satisfying fix here. Is this fix going to be committed
in CVS for next release?
------------------------------------------------------------------------
May 26, 2005 - 12:26 : adrian
hostmaster=# \df nullvalue
List of functions
Result data type | Schema | Name | Argument data types
------------------+------------+-----------+---------------------
boolean | pg_catalog | nullvalue | "any"
But it doesn't matter to me =)
------------------------------------------------------------------------
May 27, 2005 - 07:21 : Dries
Can you guys provide a patch? I don't have a PostgreSQL setup to test
it against. Will commit to DRUPAL-4-6 and HEAD.
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