django.db.utils.IntegrityError: (1452, '无法添加或更新子行：外键约束失败

Question

from django.db import models
from django.contrib.auth.models import User

以前我的模型是这样的。

class Login(models.Model):
    pid              = models.AutoField(primary_key=True)
    custom_username  = models.BooleanField(default=False)
    tnx_hash         = models.CharField(max_length=100, null=True, blank=True)

    def __str__(self):
        return self.username

然后我改成这样继承基本管理员用户 model。

class Login(User):
    pid              = models.AutoField(primary_key=True)
    custom_username  = models.BooleanField(default=False)
    tnx_hash         = models.CharField(max_length=100, null=True, blank=True)

    def __str__(self):
        return self.username

现在，当我运行 makemigrations 并迁移时，出现以下错误。

        Operations to perform:
        Apply all migrations: admin, api, auth, authtoken, contenttypes, sessions
        Running migrations:
        Applying api.0278_auto_20220318_1210...Traceback (most recent call last):
        File "/Users/soubhagyapradhan/Desktop/upwork/polyverse/polyverse_api/env/lib/python3.8/site-packages/django/db/backends/utils.py", line 84, in _execute
            return self.cursor.execute(sql, params)
        File "/Users/soubhagyapradhan/Desktop/upwork/polyverse/polyverse_api/env/lib/python3.8/site-packages/django/db/backends/mysql/base.py", line 73, in execute
            return self.cursor.execute(query, args)
        File "/Users/soubhagyapradhan/Desktop/upwork/polyverse/polyverse_api/env/lib/python3.8/site-packages/MySQLdb/cursors.py", line 206, in execute
            res = self._query(query)
        File "/Users/soubhagyapradhan/Desktop/upwork/polyverse/polyverse_api/env/lib/python3.8/site-packages/MySQLdb/cursors.py", line 319, in _query
            db.query(q)
        File "/Users/soubhagyapradhan/Desktop/upwork/polyverse/polyverse_api/env/lib/python3.8/site-packages/MySQLdb/connections.py", line 259, in query
            _mysql.connection.query(self, query)
        MySQLdb._exceptions.IntegrityError: (1452, 'Cannot add or update a child row: a foreign key constraint fails (`baby`.`#sql-16a7_6a`, CONSTRAINT `api_login_user_ptr_id_7f748092_fk_auth_user_id` FOREIGN KEY (`user_ptr_id`) REFERENCES `auth_user` (`id`))')

        The above exception was the direct cause of the following exception:

        Traceback (most recent call last):
        File "manage.py", line 22, in <module>
            main()
        File "manage.py", line 18, in main
            execute_from_command_line(sys.argv)
        File "/Users/soubhagyapradhan/Desktop/upwork/polyverse/polyverse_api/env/lib/python3.8/site-packages/django/core/management/__init__.py", line 419, in execute_from_command_line
            utility.execute()
        File "/Users/soubhagyapradhan/Desktop/upwork/polyverse/polyverse_api/env/lib/python3.8/site-packages/django/core/management/__init__.py", line 413, in execute
            self.fetch_command(subcommand).run_from_argv(self.argv)
        File "/Users/soubhagyapradhan/Desktop/upwork/polyverse/polyverse_api/env/lib/python3.8/site-packages/django/core/management/base.py", line 354, in run_from_argv
            self.execute(*args, **cmd_options)
        File "/Users/soubhagyapradhan/Desktop/upwork/polyverse/polyverse_api/env/lib/python3.8/site-packages/django/core/management/base.py", line 398, in execute
            output = self.handle(*args, **options)
        File "/Users/soubhagyapradhan/Desktop/upwork/polyverse/polyverse_api/env/lib/python3.8/site-packages/django/core/management/base.py", line 89, in wrapped
            res = handle_func(*args, **kwargs)
        File "/Users/soubhagyapradhan/Desktop/upwork/polyverse/polyverse_api/env/lib/python3.8/site-packages/django/core/management/commands/migrate.py", line 244, in handle
            post_migrate_state = executor.migrate(
        File "/Users/soubhagyapradhan/Desktop/upwork/polyverse/polyverse_api/env/lib/python3.8/site-packages/django/db/migrations/executor.py", line 117, in migrate
            state = self._migrate_all_forwards(state, plan, full_plan, fake=fake, fake_initial=fake_initial)
        File "/Users/soubhagyapradhan/Desktop/upwork/polyverse/polyverse_api/env/lib/python3.8/site-packages/django/db/migrations/executor.py", line 147, in _migrate_all_forwards
            state = self.apply_migration(state, migration, fake=fake, fake_initial=fake_initial)
        File "/Users/soubhagyapradhan/Desktop/upwork/polyverse/polyverse_api/env/lib/python3.8/site-packages/django/db/migrations/executor.py", line 227, in apply_migration
            state = migration.apply(state, schema_editor)
        File "/Users/soubhagyapradhan/Desktop/upwork/polyverse/polyverse_api/env/lib/python3.8/site-packages/django/db/migrations/migration.py", line 126, in apply
            operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
        File "/Users/soubhagyapradhan/Desktop/upwork/polyverse/polyverse_api/env/lib/python3.8/site-packages/django/db/migrations/operations/fields.py", line 104, in database_forwards
            schema_editor.add_field(
        File "/Users/soubhagyapradhan/Desktop/upwork/polyverse/polyverse_api/env/lib/python3.8/site-packages/django/db/backends/mysql/schema.py", line 98, in add_field
            super().add_field(model, field)
        File "/Users/soubhagyapradhan/Desktop/upwork/polyverse/polyverse_api/env/lib/python3.8/site-packages/django/db/backends/base/schema.py", line 522, in add_field
            self.execute(sql, params)
        File "/Users/soubhagyapradhan/Desktop/upwork/polyverse/polyverse_api/env/lib/python3.8/site-packages/django/db/backends/base/schema.py", line 145, in execute
            cursor.execute(sql, params)
        File "/Users/soubhagyapradhan/Desktop/upwork/polyverse/polyverse_api/env/lib/python3.8/site-packages/django/db/backends/utils.py", line 98, in execute
            return super().execute(sql, params)
        File "/Users/soubhagyapradhan/Desktop/upwork/polyverse/polyverse_api/env/lib/python3.8/site-packages/django/db/backends/utils.py", line 66, in execute
            return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
        File "/Users/soubhagyapradhan/Desktop/upwork/polyverse/polyverse_api/env/lib/python3.8/site-packages/django/db/backends/utils.py", line 75, in _execute_with_wrappers
            return executor(sql, params, many, context)
        File "/Users/soubhagyapradhan/Desktop/upwork/polyverse/polyverse_api/env/lib/python3.8/site-packages/django/db/backends/utils.py", line 84, in _execute
            return self.cursor.execute(sql, params)
        File "/Users/soubhagyapradhan/Desktop/upwork/polyverse/polyverse_api/env/lib/python3.8/site-packages/django/db/utils.py", line 90, in __exit__
            raise dj_exc_value.with_traceback(traceback) from exc_value
        File "/Users/soubhagyapradhan/Desktop/upwork/polyverse/polyverse_api/env/lib/python3.8/site-packages/django/db/backends/utils.py", line 84, in _execute
            return self.cursor.execute(sql, params)
        File "/Users/soubhagyapradhan/Desktop/upwork/polyverse/polyverse_api/env/lib/python3.8/site-packages/django/db/backends/mysql/base.py", line 73, in execute
            return self.cursor.execute(query, args)
        File "/Users/soubhagyapradhan/Desktop/upwork/polyverse/polyverse_api/env/lib/python3.8/site-packages/MySQLdb/cursors.py", line 206, in execute
            res = self._query(query)
        File "/Users/soubhagyapradhan/Desktop/upwork/polyverse/polyverse_api/env/lib/python3.8/site-packages/MySQLdb/cursors.py", line 319, in _query
            db.query(q)
        File "/Users/soubhagyapradhan/Desktop/upwork/polyverse/polyverse_api/env/lib/python3.8/site-packages/MySQLdb/connections.py", line 259, in query
            _mysql.connection.query(self, query)
        django.db.utils.IntegrityError: (1452, 'Cannot add or update a child row: a foreign key constraint fails (`baby`.`#sql-16a7_6a`, CONSTRAINT `api_login_user_ptr_id_7f748092_fk_auth_user_id` FOREIGN KEY (`user_ptr_id`) REFERENCES `auth_user` (`id`))')

请看一下。 我怎样才能安全地解决这个问题。 因为我的数据库中有数据，而登录表是许多表的外键。

    ERRORS:
    api.Login.groups: (fields.E304) Reverse accessor for 'api.Login.groups' clashes with reverse accessor for 'auth.User.groups'.
        HINT: Add or change a related_name argument to the definition for 'api.Login.groups' or 'auth.User.groups'.
    api.Login.user_permissions: (fields.E304) Reverse accessor for 'api.Login.user_permissions' clashes with reverse accessor for 'auth.User.user_permissions'.
        HINT: Add or change a related_name argument to the definition for 'api.Login.user_permissions' or 'auth.User.user_permissions'.
    auth.User.groups: (fields.E304) Reverse accessor for 'auth.User.groups' clashes with reverse accessor for 'api.Login.groups'.
        HINT: Add or change a related_name argument to the definition for 'auth.User.groups' or 'api.Login.groups'.
    auth.User.user_permissions: (fields.E304) Reverse accessor for 'auth.User.user_permissions' clashes with reverse accessor for 'api.Login.user_permissions'.
        HINT: Add or change a related_name argument to the definition for 'auth.User.user_permissions' or 'api.Login.user_permissions'.

Answer 1

从User model 继承是行不通的，因为它有自己的主键id 。 您在Login model 中有一个主键定义的pid 。相反，如果您只想使用User字段扩展Login model，则可以从AbstractUser class 继承。

如果要切换到Login model 作为默认用户 Model，则api_login auth_user ，使用数据迁移或 SQL 并设置AUTH_USER_MODEL = "api.Login"