Django one to one relation queryset

Question

I have following two models

class A(models.Model):
  name = models.CharField()
  age = models.SmallIntergerField()

class B(models.Model):
  a = models.OneToOneField(A)
  salary = model.IntergerField()

No I have got records both of them. I want to query Model A with known id and I want both A and B records.

The SQL query is:

SELECT A.id, A.name, A.age, B.salary
FROM A INNER JOIN B ON A.id = B.a_id
WHERE A.id=1

Please provide me django query (by using orm). I want to achieve this with one queryset.

Answer 1

q = B.objects.filter(id=id).values('salary','a__id','a__name','a__age')

this will return a ValuesQuerySet

values

values(*fields) Returns a ValuesQuerySet — a QuerySet subclass that returns dictionaries when used as an iterable, rather than model-instance objects.

Each of those dictionaries represents an object, with the keys corresponding to the attribute names of model objects.

You can actually print q.query to get the sql query behind the QuerySet, which in this case is exactly as you requested.

Answer 2

Please try this:

result = B.objects.filter(a__id=1).values('a__id', 'a__name', 'a__age', 'salary')

The result is a <class 'django.db.models.query.ValuesQuerySet'>, which is essentially a list of dictionaries with key as the field name and value as the actual value. If you want only the values, do this:

result = B.objects.filter(a__id=1).values_list('a__id', 'a__name', 'a__age', 'salary')

The result is a <class 'django.db.models.query.ValuesListQuerySet'>, and it's essentially a list of tuples.