/add/ NOT NULL 约束的 IntegrityError 失败：myApp_bookdetail.manager_id

Question

I am having IntegrityError at /add/ NOT NULL constraint failed: myApp_bookdetail.manager_id

class BookDetail(models.Model):
    manager = models.ForeignKey(User, on_delete=models.CASCADE, default=None, null=True)
    name = models.CharField(max_length=100)
    author = models.CharField(max_length=100)
    inum = models.IntegerField()

Answer 1

If your are using form.save then here's my answer. Whenever there's a ForeignKey in your model, then directly saving the model using form.save() causes this error. So this is how we save models with ForeignKey -

book = form.save(commit = False)
book.manager = request.user
book.save()