Storing arrays in Django Models (not PostGreSQL)

Question

I want a field in my Django model to store array data.

For instance consider a model that stores Student data. I want an array field that stores the marks of that student as an integer array. What can I do?

I am not using PostGreSQL so I cannot use ArrayField.

class Student(models.Model):
    ...
    ...
    marks = models.?

Typically you don't. Even for PostgreSQL not the best way. Usually you make a model Mark, with a ForeignKey to Student. — willeM_ Van Onsem
– willeM_ Van Onsem, Commented Aug 4, 2020 at 21:08

willeM_ Van Onsem · Accepted Answer · 2020-08-04 21:11:47Z

2

Typically you don't. Even for PostgreSQL not advisable. Relational databases are usually better to work with scalar values in columns.

You can make a model Mark, with a ForeignKey [Django-doc] to Student, for example:

class Student(models.Model):
    # …

class Mark(models.Model):
    mark = models.IntegerField()
    student = models.ForeignKey(
        Student,
        related_name='marks'
        on_delete=models.CASCADE
    )

You can then create for example marks for a student:

student = Student.objects.create()
Mark.objects.create(student=stud, mark=7)
Mark.objects.create(student=stud, mark=8)

Then you access the Mark objects of the student with:

student.marks.all()

answered Aug 4, 2020 at 21:11

willeM_ Van Onsem

482k33 gold badges483 silver badges624 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Adhishwar Over a year ago

Alternatively, we can also use the jsonfield python library. We can do the following, from jsonfield import JSONField class Student(models.Model): ... ... data = JSONField(default = list) More can be found out at (pypi.org/project/jsonfield)

willeM_ Van Onsem Over a year ago

@Adhishwar: I would advise not to do this. A JsonField is behind the curtains just a CharField with transparent wrapping between the string/data. As a result the database does not know what it stores. You thus can not order Students by average grade for example with a database query.

Collectives™ on Stack Overflow

Storing arrays in Django Models (not PostGreSQL)

1 Answer 1

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related