CODEWITHSUNDEEP
pythondjangodjango-models
user3384985
user3384985

Reputation: 3017

How to join multiple records of a model to another model in Django?

I need to set some tags to a question. In Question model i use Tag as ForeignKey -

class Tag(models.Model):
    tag_text = models.CharField(max_length = 200)

class Question(models.Model):
    tag = models.ForeignKey(Tag, on_delete = models.CASCADE)

What i see in back end for a Question can select one Tag but i want a single Question can select multiple Tags.

I am confused what it would be - ManyToMany / OneToMany /...

Thanks

Upvotes: 0

Views: 63

Answers (1)

Sanket Sudake
Sanket Sudake

Reputation: 771

Use ManyToMany relationship.

As one Question can have multiple tags, as well as one Tag can be there in multiple questions.

class Tag(models.Model):
    tag_text = models.CharField(max_length = 200)

class Question(models.Model):
    tag = models.ManyToManyField(Tag)

Relative queries:

  1. Add tag to Question instance as,

    quest_instance.tags.add(your_tag_instance)

  2. To get all tags for question,

    quest_instance.tags.all()

  3. Get all questions for particular tag,

    tag_inst.question_set.all()

Note: Relative queries may require minor updates.

Upvotes: 3

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