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
29021	Weird behavior of foreign key lookup and annotate F expression	Paul	nobody	"
{{{
class Sentence(Model):
    name = CharField()
    
class Tokens(Model):
    token = CharField()
    sentence = ForeignKey(Sentence, related_name='tokens')
}}}



{{{
Sentence.objects.annotate(n=Count('tokens', distinct=True)).filter(n=5).filter(tokens__name__in=['se']).annotate(n0=F('tokens')).filter(tokens__name__in=['faire']).annotate(n1=F('tokens')).filter(tokens__name__in=['faire']).annotate(n2=F('tokens')).filter(tokens__name__in=['un']).annotate(n3=F('tokens')).filter(tokens__name__in=['avoir']).annotate(n4=F('tokens'))
}}}


Above code generates the following query:


{{{
    SELECT ""sentence"".""id"", ""sentence"".""name"" COUNT(DISTINCT ""token"".""id"") AS ""n"", T3.""id"" AS ""n0"", T4.""id"" AS ""n1"", T4.""id"" AS ""n2"", T6.""id"" AS ""n3"", T6.""id"" AS ""n4"" FROM ""sentence"" LEFT OUTER JOIN ""token"" ON (""sentence"".""id"" = ""token"".""sentence_id"") INNER JOIN ""token"" T3 ON (""sentence"".""id"" = T3.""sentence_id"") INNER JOIN ""token"" T4 ON (""sentence"".""id"" = T4.""sentence_id"") INNER JOIN ""token"" T5 ON (""sentence"".""id"" = T5.""sentence_id"") INNER JOIN ""token"" T6 ON (""sentence"".""id"" = T6.""sentence_id"") INNER JOIN ""token"" T7 ON (""sentence"".""id"" = T7.""sentence_id"") WHERE (T3.""name"" IN (se) AND T4.""name"" IN (faire) AND T5.""name"" IN (un) AND T6.""name"" IN (avoir) AND T7.""name"" IN (faire)) GROUP BY ""word_frword"".""id"", T3.""id"", T4.""id"", T6.""id"" HAVING COUNT(DISTINCT ""token"".""id"") = 5
}}}


Why is numbering so strange (starts with `T3`)? But moreover why `n2` is assigned to `T4`, not `T5`? Same for `n4` and `T6`. Looks like numbers go by 2.

What I want to accomplish is capture token id on each step of inner join. It works when there are one join, but then it breaks.

Any suggestions?"	Bug	new	Database layer (models, ORM)	1.10	Normal		django-model, foreign-key		Unreviewed	0	0	0	0	0	0