python-3.x - django 模型在每次迁移时都会收到 Alter Field 警报

Question

每次运行命令 python manage.py makemigrations 时，我都会收到 alter filed 警报 我还删除了我的数据库旧迁移文件，但警报仍然存在 谁知道我该如何解决这个问题问题？

Migrations for 'assignment':
  assignment/migrations/0012_auto_20201016_0754.py
    - Alter field city on assignment
    - Alter field status on assignment

class Assignment(models.Model):

    CITY_SELECT = {
        ('i', 'Islamabad'),
        ('l', 'Lahore'),
        ('m', 'Multan'),
        ('k', 'Karachi'),
        ('q', 'Queta'),
        ('p', 'Pashawar')
    }

    STATUS_SELECT = {
        ('p', 'Pendding'),
        ('d', 'Done'),
        ('i', 'In field'),
        ('c', 'Cancel')
    }

    place = models.CharField(max_length=100)
    desc = models.CharField(max_length=500)
    reporter = models.ForeignKey(User, on_delete=models.SET_NULL, null=True)
    created_on = models.DateTimeField(auto_now_add=True)
    assign_time = models.DateTimeField(auto_now=False, null=True)
    city = models.CharField(choices=CITY_SELECT, max_length=9)
    status = models.CharField(choices=STATUS_SELECT, max_length=8)

Answer 1

很可能该集合每次都以不同的顺序“打乱”，使得选择不可预测。如果多次运行 Python 进程，每次的哈希常数都不一样。您可以使用列表，这将确保顺序始终相同:

class Assignment(models.Model):
    
    CITY_SELECT = <b>[</b>  # ← use a list
        ('i', 'Islamabad'),
        ('l', 'Lahore'),
        ('m', 'Multan'),
        ('k', 'Karachi'),
        ('q', 'Queta'),
        ('p', 'Pashawar')
    <b>]</b>
    
    STATUS_SELECT = <b>[</b>  # ← use a list
        ('p', 'Pendding'),
        ('d', 'Done'),
        ('i', 'In field'),
        ('c', 'Cancel')
    <b>]</b>

    place = models.CharField(max_length=100)
    desc = models.CharField(max_length=500)
    reporter = models.ForeignKey(User, on_delete=models.SET_NULL, null=True)
    created_on = models.DateTimeField(auto_now_add=True)
    assign_time = models.DateTimeField(auto_now=False, null=True)
    city = models.CharField(choices=CITY_SELECT, max_length=9)
    status = models.CharField(choices=STATUS_SELECT, max_length=8)