id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
15624	annotate + aggregate produces incorrect sql statement	zeroos <232002@…>	fhahn	"I have a following model: 
{{{
class Solution(models.Model): 
    griddler = models.ForeignKey(Griddler) 
    user = models.ForeignKey(User) 
    user_time = models.IntegerField(null=True) 
    date = models.DateTimeField(auto_now_add=True) 
class Griddler(models.Model): 
    .... 
    solved_by = models.ManyToManyField(Uesr, through='Solution') 
    .... 
}}}


What I am trying to do is to find the Griddler that has the biggest 
avg user time. I've written the following query: 
Solution.objects.values('griddler').annotate(a=Avg('user_time')).aggregate( Max('a')) 

Unfortunately, after executing it I get 

DatabaseError: (1064, ""You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'FROM (SELECT `griddlers_solution`.`griddler_id` AS `griddler_id`, AVG(`griddlers' at line 1"") 

{{{
>>> connection.queries[-1] 
{'time': '0.000', 'sql': u'SELECT  FROM (SELECT 
`griddlers_solution`.`griddler_id` AS `griddler_id`, 
AVG(`griddlers_solution`.`user_time`) AS `a` FROM `griddlers_solution` 
GROUP BY `griddlers_solution`.`griddler_id`, 
`griddlers_solution`.`griddler_id` ORDER BY NULL) subquery'} 
}}}

The problem is that Max('a') is skipped in the sql query. Instead of :
{{{
SELECT  FROM (SELECT ...
}}}
It should look like this: 
{{{
SELECT Max(`a`) FROM (SELECT... 
}}}

I am using Django from SVN (pulled today, 16.03.11) and MySQL backend.

{{{
>>> django.get_version() 
'1.3 beta 1'
}}}"	Bug	closed	Database layer (models, ORM)	dev	Normal	fixed	aggregate sql syntax error	flo@… John Milner	Ready for checkin	1	0	0	0	0	0