Doubt in the usage of bulk_create with update_conflicts=True

Using Django Using the ORM
1

So I’m currently facing an issue where I’m supposed to create or update in bulk a few records. Thus I added unique constraints to my model and tried implementing a bulk_create with update_conflicts as True. But even when it faces an issue with inserting due to Unique constraints, it is not updating it.

My model:

class EventAttendance(db.SoftDeleteWithBaseModel):
    """
    Store the assessment report of the trainee
    """

    sub_batch = models.ForeignKey(
        "hubble.SubBatch", on_delete=models.CASCADE, related_name="event_attendance"
    )
    batch = models.ForeignKey(
        "hubble.Batch", on_delete=models.CASCADE, related_name="event_attendance"
    )
    event = models.ForeignKey("hubble.Event", on_delete=models.CASCADE, related_name="event_type")
    user = models.ForeignKey(
        "hubble.User", on_delete=models.CASCADE, related_name="event_attendance"
    )
    updated_by = models.ForeignKey(
        "hubble.User", on_delete=models.CASCADE, related_name="updated_event_attendance", null=True
    )
    present_status = models.BooleanField(default=False, verbose_name="Present status")
    trainee_arrival_time = models.TimeField(null=True)

    class Meta:
        """
        Meta class for defining class behavior and properties.
        """

        db_table = "event_attendance"
        constraints = [
            models.UniqueConstraint(
                fields=["user", "event", "deleted_at"],
                name="unique trainee attendance with soft delete",
            ),
            models.UniqueConstraint(
                fields=["user", "event"],
                name="unique trainee attendance",
                condition=db.models.Q(deleted_at__isnull=True),
            ),
        ]

My logic to either create or update:

def bulk_create_event_attendance(batch, user_ids, request_user, event, data_frame):
    """
    Used to bulk update the attendance for an event.
    """
    attendance_instances_to_be_created_or_updated = []
    for row in range(len(data_frame)):
        attendance_instances_to_be_created_or_updated.append(
            EventAttendance(
                batch=batch,
                user_id=user_ids[row]["id"],
                sub_batch_id=user_ids[row]["intern_details__sub_batch_id"],
                event=event,
                trainee_arrival_time=data_frame["Time"][row],
                present_status=data_frame["Present Status"][row].lower() == "yes",
                updated_by=request_user,
                updated_at=timezone.now(),
            )
        )
    EventAttendance.objects.bulk_create(
        attendance_instances_to_be_created_or_updated,
        update_conflicts=True,
        update_fields=["present_status", "trainee_arrival_time", "updated_at", "updated_by"],
        unique_fields=["user", "event", "deleted_at"],
    )

Error raised:
duplicate key value violates unique constraint “unique trainee attendance”
DETAIL: Key (user_id, event_id)=(273, 1) already exists.

Can someone help me to fix this issue?

1 Like
2

There was a change to behavior on update_conflicts in django 5.0. Not sure if this would affect your outcome but have a look.

3

I have the same problem, any update about it

4

Well this happens when there are multiple objects in with the same values in the initial array.
In this case, you must have two EventAttendance with user_id=273 and event_id = 1 in
attendance_instances_to_be_created_or_updated. In order to work, it should be ONLY ONE!