Django: union of different queryset on the same model

Question

I\'m programming a search on a model and I have a problem.

My model is almost like:

class Serials(models.Model):
    id = models.AutoField(primary_ke         


        

Answer 1

You should also be able to do qs1 | qs2 | qs3 | qs4. This will give you duplicates, however.

What you might want to look into is Q() objects:

from django.db.models import Q
value = "new"
Serials.objects.filter(Q(name__startswith=value) |
                       Q(code__startswith=value) |
                       Q(name__contains=value) |
                       Q(code__contains=value).distinct()

I'm not sure if it will handle the ordering if you do it this way, as this would rely on the db doing that.

Indeed, even using qs1 | qs2 may cause the order to be determined by the db. That might be the drawback (and reason why you might need at least two queries).

Answer 2

You can make those four queries and then chain them inside your program:

result = itertools.chain(qs1, qs2, qs3, qs4)

but this doesn't seem to nice because your have to make for queries.

You can also write your own sql using raw sql, for example:

Serials.objects.raw(sql_string)

Also look at this:

How to combine 2 or more querysets in a Django view?