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
31940	Order of WHERE clauses do not match the order of the arguments to .filter().	Tommy Li	nobody	"With the following sample model

{{{#!python
class MyModel(models.Model):
    a_field = models.IntegerField()
    b_field = models.IntegerField()
}}}

If I run the following query:
{{{#!python
MyModel.objects.filter(b_field = 1, a_field = 2)
}}}
the SQL that it generates is 
{{{
SELECT ""mymodel"".""a_field"", ""mymodel"".""b_field
FROM ""mymodel""
WHERE (""mymodel"".""a_field"" = 2 AND ""mymodel"".""b_field"" = 1)
}}}

I would expect the order of the clauses in the WHERE statement to match the order of arguments passed to the filter statement. In my case, `b_field` has a much higher cardinality than `a_field` and I want the query to use an index I have on `(b_field, a_field)`

After some experimentation, it looks like the WHERE clauses are ordered alphabetically by column name. Is that explicitly intended, or is it just a side effect of some implementation detail?

A workaround is to run 
{{{#!python
MyModel.objects.filter(b_field = 1).filter(a_field = 2)
}}}
But this is pretty inconvenient if you just want to run a .get, you would have to build out a verbose .filter().filter().first() query"	Cleanup/optimization	closed	Database layer (models, ORM)	3.0	Normal	wontfix			Unreviewed	0	0	0	0	0	0