我想在涉及到另一个模型对象引用的模型上添加约束。 在下面的代码中,我希望在ProjectMember模型上将project_member字段限制为与项目模型中的project_creator不同。
class User(models.Model):
fullname = models.CharField(max_length=200)
email = models.EmailField(max_length=254)
password = models.CharField(max_length=254)
class Project(models.Model):
name = models.CharField(max_length=200)
timestamp = models.DateTimeField("date created", auto_now=True)
project_creator = models.ForeignKey(User, on_delete=models.CASCADE)
class ProjectMember(models.Model):
project = models.ForeignKey(Project, on_delete=models.CASCADE)
project_member = models.ForeignKey(
User,
on_delete=models.CASCADE,
verbose_name="member of the project"
)
class Meta:
order_with_respect_to = 'user_member'
constraints = [
models.CheckConstraint(check= ,
name='project creator not project member'),
]
答案 0 :(得分:3)
您可以像这样将其添加到Q对象中,
class Meta:
order_with_respect_to = 'user_member'
constraints = [
models.CheckConstraint(check=~Q(project_member_id=project__project_creator_id) ,
name='project creator not project member'),
]
希望这会有所帮助!