CODEWITHSUNDEEP
djangoorminner-joindjango-ormeager-loading
Muhammed Hasan Celik
Muhammed Hasan Celik

Reputation: 682

Django eager loading in many to many

Those are many models

class FacultyMember(models.Model):
    # some attributes

class Publication(models.Model):
    # some attributes
    author = models.ManyToManyField(FacultyMember, blank=True)

class Project(models.Model):
    # some attributes
    researchers = models.ManyToManyField(FacultyMember, blank=True)

And I want to get FacultyMember with all related project and publication with eager loading.

I try some thing like following code 

FacultyMember.objects.filter(
    pk=id,
    first_name=first_name,
    last_name=last_name
).select_related('project_set').select_related('publication_set')

However it do not working.

How to join related field in django orm with eager loading.

Upvotes: 15

Views: 11743

Answers (1)

Geo Jacob
Geo Jacob

Reputation: 6009

Manytomany uses prefetch_related;

FacultyMember.objects.filter(
pk=id,
first_name=first_name,
last_name=last_name
).prefetch_related('project_set').prefetch_related('publication_set')

Refer here https://docs.djangoproject.com/en/1.8/ref/models/querysets/#prefetch-related

Upvotes: 20

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