Can Django make this multiple tables query in a single statement?

Let simplify the problem. Say I have two models:


class Man(models.Model):
   # some fields

class Job(models.Model):
   man = models.ForeignKey(Man)
   # other fields

Here, my logic is that, some man may have a job, some may not. Now I want to make a query to select men with the info if the man have a job.

If I write the query in SQL, then something like:

select m.*, j.id from man m left join job j on m.id=j.id where m.some_condition

So that if j.id is null, then the man has no job. How to make this query in Django ORM?

men_with_jobs = Man.objects.exclude(job_set=None)

.exclude(job_set=None) is essentially just syntactic sugar to say .filter(job_set__isnull=False) (which kind of is an instance of following reverse relationships), where job_set is the implicit name of the reverse relationship from Man back to the Job foreignkey.

This will leave you with a queryset containing only Man instances that have at least one Job instance referencing them.

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