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
13280	postgresql exclude issue	Sergey Dobrov	nobody	"Hello.

Sorry, I can't make simple testcase for my issue, so I'll state it as is.

I have QuerySet like this:


{{{
qforum = Forum.objects.filter(category=category).exclude(
              forumlink__campaign_link_keyword__campaign_link=forumlink.campaign_link_keyword.campaign_link)
}}}

My models look like this:

{{{
class Category(models.Model):
    name = models.CharField(max_length=10)

class Forum(models.Model):
    category = models.ForeignKey(Category)

class CampaignLink(models.Model):
    pass

class CampaignLinkKeyword(models.Model):
    campaign_link = models.ForeignKey(CampaignLink)

class ForumLink(models.Model):
    forum = models.ForeignKey(Forum, null=True, blank=True)
    campaign_link_keyword = models.ForeignKey(CampaignLinkKeyword)
    status = models.Charfield(max_length=10)
}}}

Django produces next SQL query for my QuerySet:

{{{
SELECT ""targets_forum"".""id"", ""targets_forum"".""url"", ""targets_forum"".""pr"", ""targets_forum"".""category_id"", ""targets_forum"".""status"", ""targets_forum"".""added"", ""targets_forum"".""modified"", ""targets_forum"".""username"", ""targets_forum"".""password"", ""targets_forum"".""email"", ""targets_forum"".""activation_url"" 

FROM ""targets_forum"" WHERE 
(""targets_forum"".""category_id"" = 10  AND NOT 
  (""targets_forum"".""id"" IN 
    (SELECT U1.""forum_id"" FROM ""campaigns_forumlink"" U1 INNER JOIN ""campaigns_campaignlinkkeyword"" U2 ON (U1.""campaign_link_keyword_id"" = U2.""id"") 
      WHERE U2.""campaign_link_id"" = 46 ) AND NOT (""targets_forum"".""id"" IS NULL) AND ""targets_forum"".""id"" IS NOT NULL)) LIMIT 21
}}}

But it has no results because subquery returns null values too, so this query works fine:

{{{
SELECT ""targets_forum"".""id"", ""targets_forum"".""url"", ""targets_forum"".""pr"", ""targets_forum"".""category_id"", ""targets_forum"".""status"", ""targets_forum"".""added"", ""targets_forum"".""modified"", ""targets_forum"".""username"", ""targets_forum"".""password"", ""targets_forum"".""email"", ""targets_forum"".""activation_url"" 

FROM ""targets_forum"" WHERE 
(""targets_forum"".""category_id"" = 10  AND NOT 
  (""targets_forum"".""id"" IN 
    (SELECT U1.""forum_id"" FROM ""campaigns_forumlink"" U1 INNER JOIN ""campaigns_campaignlinkkeyword"" U2 ON (U1.""campaign_link_keyword_id"" = U2.""id"") 
      WHERE U2.""campaign_link_id"" = 46 AND U1.""forum_id"" IS NOT NULL) AND NOT (""targets_forum"".""id"" IS NULL) AND ""targets_forum"".""id"" IS NOT NULL)) LIMIT 21
}}}

I wrote workaround with raw sql query usage and it works but I hope that we can fix this issue. I ready to answer any questions.

Btw, ""AND NOT (""targets_forum"".""id"" IS NULL) AND ""targets_forum"".""id"" IS NOT NULL"" looks funny :)"	Bug	closed	Database layer (models, ORM)	1.1	Normal	fixed			Accepted	0	0	0	0	0	0