Django query filter combining AND and OR with Q objects don't return the expected results

Question

I try to combine AND and OR in a filter using Q objects. It looks like that the | behave like an AND. This is related to the previous annotate which is run in the same query and

Answer 1

Try adding parentheses to explicitly specify your grouping? As you already figured out, multiple params to filter() are just joined via AND in the underlying SQL.

Originally you had this for the filter:

[...].filter(
    Q(hide=False) & Q(deleted=False),
    Q(stock=False) | Q(quantity__gte=1))

If you wanted (A & B) & (C | D) then this should work:

[...].filter(
    Q(hide=False) & Q(deleted=False) &
    (Q(stock=False) | Q(quantity__gte=1)))

Answer 2

OK, no success here or on #django. So I choose to use a raw SQL query to solve this problem...

Here the working code:

types_list = Type.objects.raw('SELECT * FROM equipment_type
    LEFT JOIN (                                            
        SELECT type_id, SUM(quantity) AS qty               
        FROM equipment_item                                
        GROUP BY type_id                                   
    ) T1                                                   
    ON id = T1.type_id                                     
    WHERE hide=0 AND deleted=0 AND (T1.qty > 0 OR stock=0) 
    ')

Answer 3

Here's my example of complicated query, I hope you find it helpful

or_condition = Q()
and_condition = Q(company=request.user.profile.company)

for field in MyModel._meta.get_fields():
    if field.name != 'created_on' and field.name != 'company':
        or_condition.add(
            Q(**{"{}__icontains".format(field.name): query}), Q.OR)

and_condition.add(or_condition2, Q.AND)
MyModel.objects.filter(and_condition)

The problem with this method is that you get an empty (AND: ) case in your or_condition. It doesn't affect the query at all, but it annoys me! My current solution is as follows

import operator
from functools import reduce

and_condition = Q(company=request.user.profile.company)
or_condition = reduce(operator.or_, (Q(**{"{}__icontains".format(field.name): query})
                                     for field in MyModel._meta.get_fields() if field.name != 'created_on' and field.name != 'company'))

and_condition.add(or_condition, Q.AND)
MyModel.objects.filter(and_condition)

Answer 4

This answer is late but could be helpful to a lot of guys out there.

[...].filter(hide=False & deleted=False)
.filter(Q(stock=False) | Q(quantity__gte=1))

This will generate something similar to

WHERE (hide=0 AND deleted=0 AND (T1.qty > 0 OR stock=0))