Python 如何修复迁移模型'；id'；Django 2.2中的字段？

我有一个Django模型，它不包含“id”字段，但在我之前迁移的MySQL实例中，出于某种原因，它显示了一个“id”字段。我不断听到一个错误，说：

You are trying to add a non-nullable field 'id' to discussions without a default; we can't do that (the database n
eeds something to populate existing rows).

所以我去检查了我的

models.py

文件，它没有“id”字段：

class Discussions(models.Model):

    #team_id = models.ForeignKey(Teams, null=True, on_delete=models.CASCADE)
    login = models.CharField(max_length=30, null=True)
    uid = models.PositiveIntegerField(primary_key=True)
    title = models.CharField(max_length=30, null=True)
    body = models.CharField(max_length=500, null=True)
    comments = models.CharField(max_length=30, null=True)
    updated_at = models.CharField(max_length=21, null=True)

但它出现在我的MySQL

descripe

语句中：

+------------+--------------+------+-----+---------+----------------+
| Field      | Type         | Null | Key | Default | Extra          |
+------------+--------------+------+-----+---------+----------------+
| id         | int(11)      | NO   | PRI | NULL    | auto_increment |
| login      | varchar(30)  | YES  |     | NULL    |                |
| comments   | varchar(30)  | YES  |     | NULL    |                |
| updated_at | varchar(21)  | YES  |     | NULL    |                |
| body       | varchar(500) | YES  |     | NULL    |                |
| title      | varchar(30)  | YES  |     | NULL    |                |
+------------+--------------+------+-----+---------+----------------+

当我删除表以尝试重新同步数据库时，我收到一个错误，错误是：

django.db.utils.ProgrammingError: (1146, "Table 'my_project.app_discussions' doesn't exist")

理想情况下，我希望有某种方法可以让视图中的

uid

变量实际加载到表示

id

字段的db实例中

        # tree->tuples->list of tuples
        json_tree = objectpath.Tree(data)
        login = tuple(json_tree.execute("$..login"))
        uid = tuple(json_tree.execute("$..id"))
        title = tuple(json_tree.execute("$..title"))
        body = tuple(json_tree.execute("$..body"))
        comments = tuple(json_tree.execute("$..comments_count"))
        updated_at = tuple(json_tree.execute("$..updated_at"))

        # took out `uid`
        parsed_list = list(zip(login, uid, title, body, comments, updated_at))

        # LOADING PHASE
        load_data = []

        # took out `u`
        for l, t, i, b, c, u in zip(login, uid, title, body, comments, updated_at):

            load_data.append(Discussions(l, t, i, b, c, u))

        Discussions.objects.bulk_create(load_data)

---

为什么我不能将这个新模式迁移到MySQL？为什么这个

uid

字段在我之前使用过之后没有通过ORM映射到ID字段中？感谢您的帮助。

id是主键，不能为空。 当您在以前的迁移中添加可为空的

id

字段时，您需要更改以前的迁移，或者只需在模型中添加新字段，然后再次运行迁移

id = models.IntegerField(null=False, primary_key=True)