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I am trying to enforce a constraint upon a Vote model in my Django application, namely that a user cannot vote more than once the same object.

To do so I am using unique_together :

class Vote(models.Model):
    vote = models.SmallIntegerField(choices=VOTES, null=True, blank=True)
    user = models.ForeignKey(User, on_delete=models.CASCADE,
        related_name="user_votes")
    definition = models.ForeignKey(Definition, on_delete=models.CASCADE,
        related_name="definition_votes")
    class Meta:
        # Ensure user cannot vote more than once.
        unique_together = ["user", "definition"]
This works, I think.
However, in Django's documentation for unique_together it is noted that
UniqueConstraint provides more functionality than
unique_together. unique_together may be deprecated in the future.
How can I substitute the above code using unique_together with code using UniqueConstraint?
The biggest confusion is the UniqueConstraint documentation can be arrived at directly from unique_togther, but it skips the Metas.constraint documentation:
constraints
Options.constraints
A list of constraints that you want to define on the model:
from django.db import models
class Customer(models.Model):
    age = models.IntegerField()
    class Meta:
        constraints = [
            models.CheckConstraint(check=models.Q(age__gte=18), name='age_gte_18'),
The sample code quickly tells you how to use the constraints.
        
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