Django model 数据约束 结束时间大于开始时间

class Task(models.Model):
    taskStartTime = models.DateTimeField(verbose_name='开始时间')
    taskEndTime = models.DateTimeField(verbose_name='结束时间')

    def __str__(self):
        return self.taskName

class Task(models.Model):
    taskStartTime = models.DateTimeField(verbose_name='开始时间')
    taskEndTime = models.DateTimeField(verbose_name='结束时间')
    
    class Meta:
    verbose_name = '任务管理'
    verbose_name_plural = verbose_name
    constraints = [
        models.CheckConstraint(
            check=Q(taskStartTime__lte=F('taskEndTime')), name='datetimecheck'
        ),
    ]
    
    def __str__(self):
        return self.taskName