[FIXED] Model instance doesn't check fields Integrity

Issue

Consider the model below

class Faculty(models.Model):
     name = models.CharField(max_length=255)
     short_name = models.CharField(max_length=15)
     description = models.CharField(max_length=512)
     logo = models.ImageField(upload_to=faculty_upload_to, null=True)

That I do Faculty.objects.create() or

faculty = Faculty()
faculty.save()

this creates an empty entry in the database

>>> from universities.models import *
>>> Faculty.objects.create()
<Faculty: Faculty object (2)>

Why doesn't Django give me an integrity error? I am using Django 5.0.

Solution

CharFields default to an empty string (""), which is a valid value for a VARCHAR column.

You may consider adding a CheckConstraint if you want to validate values at the database level:

class Faculty(models.Model):
    name = models.CharField(max_length=255)
    short_name = models.CharField(max_length=15)
    description = models.CharField(max_length=512)
    logo = models.ImageField(upload_to=faculty_upload_to, null=True)


    class Meta:
        constraints = [
            models.CheckConstraint(check=~Q(name="")),
            models.CheckConstraint(check=~Q(short_name="")),
            models.CheckConstraint(check=~Q(description="")),
        ]

Answered By - Selcuk