问题
class ModelA:
m2m1 = Foreignkey relatedname = 'm2ms'
We can get m2m1 objects using:
modela_instance.m2ms.all()
Sample output:
for x in ModelA.objects.all():
print x.m2ms.all().values_list('id', Flat=True)
1,2,3
1,
[]
2
4,5
So, if I want fetch all instances whose m2ms has ids 1,2,3 (can have more too). Then I can do this:
ModelA.objects.filter(m2ms__id=1).filter(m2ms__id=2).filter(m2ms__id=3)
How can I do this with Q ?
ModelA.objects.filter(Q(some_boolean=True, simple_field=5) | Q(some_boolean=False, here m2ms should be 1,2,3 lets say))
From above requirement, I mean:
It should return records when (some_boolean=True, simple_field=5) OR some_boolean=False, m2ms should have 1,2,3(can have more).
Output:
If some_boolean=True, then we dont bother about m2ms. These records should have simple_field with value 5
If some_boolean=False, then for all records, each_record.m2ms.all().values_list('id', Flat=True) should contains 1,2,3. For example: 1)[1,2,3], 2)[1,2,3,4], 3)[1,2,3,5,6,7]
Please let me know for more clarification.
来源：https://stackoverflow.com/questions/24191563/django-filter-on-many-to-many-along-with-q