Counting rows from a big mysql query (zend) - mysql

Question

I a developing in zend and have a rather large mysql query. The query works fine and i get the list I expect. I am doing this using Select->Where.... below is the query.
SELECT DISTINCT `d`.* FROM `deliverable` AS `d` INNER JOIN `groups` AS `g1` ON d.id = g1.deliverable_id INNER JOIN `groupmembers` AS `gm1` ON g1.id = gm1.group_id LEFT JOIN `connection` AS `c` ON d.id = c.downstreamnode_id LEFT JOIN `deliverable` AS `d1` ON c.upstreamnode_id = d1.id INNER JOIN `deliverable` AS `d2` ON CASE WHEN d1.id IS NULL THEN d.id ELSE d1.id END = d2.id INNER JOIN `groups` AS `g` ON d2.id = g.deliverable_id INNER JOIN `groupmembers` AS `gm` ON g.id = gm.group_id WHERE (g1.group_type = 100) AND (gm1.member_id = 1) AND (c.downstreamnode_id IS NULL OR d.restrict_access = 1) AND (g.group_type = 100 OR g.group_type = 110) AND (gm.member_id = 1) AND (d.deliverable_type = 110 OR d.deliverable_type = 100) GROUP BY CASE WHEN c.downstreamnode_id IS NULL THEN d.id ELSE c.downstreamnode_id END
Only problem is when I try to count the rows in a mysql query I only get 1 returned. below is the query
SELECT DISTINCT count(*) AS `rowCount` FROM `deliverable` AS `d` INNER JOIN `groups` AS `g1` ON d.id = g1.deliverable_id INNER JOIN `groupmembers` AS `gm1` ON g1.id = gm1.group_id LEFT JOIN `connection` AS `c` ON d.id = c.downstreamnode_id LEFT JOIN `deliverable` AS `d1` ON c.upstreamnode_id = d1.id INNER JOIN `deliverable` AS `d2` ON CASE WHEN d1.id IS NULL THEN d.id ELSE d1.id END = d2.id INNER JOIN `groups` AS `g` ON d2.id = g.deliverable_id INNER JOIN `groupmembers` AS `gm` ON g.id = gm.group_id WHERE (g1.group_type = 100) AND (gm1.member_id = 1) AND (c.downstreamnode_id IS NULL OR d.restrict_access = 1) AND (g.group_type = 100 OR g.group_type = 110) AND (gm.member_id = 1) AND (d.deliverable_type = 110 OR d.deliverable_type = 100) GROUP BY CASE WHEN c.downstreamnode_id IS NULL THEN d.id ELSE c.downstreamnode_id END
i generate this from by using the same 'select' that generated the first query but I reset the columns and add count in.
$this->getAdapter()->setFetchMode(Zend_Db::FETCH_ASSOC);
$select
->reset( Zend_Db_Select::COLUMNS)
->columns(array('count('.$column.') as rowCount'));
$rowCount = $this->getAdapter()->fetchOne($select);
This method works fine for all my other queries only this one i am having trouble with. I suspect it has something to do the 'CASE' I have in there but it is strange because I am getting the correct rows the the first query. Any ideas. Thanks.
FYI below are two queries that I have working successfully.
SELECT DISTINCT `po`.* FROM `post` AS `po` INNER JOIN `postinfo` AS `p` ON po.postinfo_id = p.id WHERE (p.creator_id = 1) ORDER BY `p`.`date_created` DESC
SELECT DISTINCT count(*) AS `rowCount` FROM `post` AS `po` INNER JOIN `postinfo` AS `p` ON po.postinfo_id = p.id WHERE (p.creator_id = 1) ORDER BY `p`.`date_created` DESC
In this one I have 4 rows returned in the first query and 'int 4' returned for the second one. Does anyone know why it doesnt work for the big query?

Answer 1

Move your DISTINCT.
SELECT COUNT(DISTINCT `po`.*) AS `rowCount` ...

Answer 2

Ok figured it out It was the GROUP BY that was causing only 1 result to be returned. Thanks Interrobang for you help I am sure that using DISTINCT incorrectly will have caused me a headache in the future.

Answer 3

Try using SQL_CALC_FOUND_ROWS in your query?
http://dev.mysql.com/doc/refman/5.0/en/information-functions.html#function_found-rows
Using SQL_CALC_FOUND_ROWS is mysql-specific, but it's pretty nice for getting a full record count even when your initial query contains a limit. Once you get the count, don't include SQL_CALC_FOUND_ROWS in subsequent queries for extra records since that will cause extra load on your query.
Your initial query would be:
SELECT SQL_CALC_FOUND_ROWS DISTINCT `d`.* FROM `deliverable` AS `d` INNER JOIN `groups` ...
You'll have to do a subsequent call after your initial query executes to get the count by doing a SELECT FOUND_ROWS().
If you do a little searching, you'll find someone who extended Zend_Db_Select to include this ability.