on_delete='CASCADE'好像没有效果

Question

我有两个模型 User 和 Role 之间的多对多关系，通过中介 table、UserRoleThrough 实现，它有两个 ForeignKeyFields：一个引用 User，另一个引用 Role。据我从文档中了解到，ON DELETE functionality is supported by initializing ForeignKeyField with an on_delete argument. Though it's not very clear what values on_delete can take, the documentation 给出了一个示例，例如'CASCADE'。话虽这么说，on_delete='CASCADE' 似乎没有效果，因为尝试从父 table 之一删除一行会引发错误。

peewee.IntegrityError: FOREIGN KEY constraint failed

使用数据库浏览器检查生成的模式显示外键未使用 ON DELETE 声明。

CREATE TABLE "userrolethrough" (
    "id" INTEGER NOT NULL PRIMARY KEY,
    "user_id" INTEGER NOT NULL,
    "role_id" INTEGER NOT NULL,
     FOREIGN KEY ("user_id") REFERENCES "user" ("id"),
     FOREIGN KEY ("role_id") REFERENCES "role" ("id")
)

那么我做错了什么？我如何让 on_delete 工作？这是使用 Python 3.6 和 Peewee 3.0.2 的最小可重现示例。

import peewee

db_proxy = peewee.Proxy()

class BaseModel(peewee.Model):
    class Meta:
        database = db_proxy

class User(BaseModel):
    name = peewee.CharField()

class Role(BaseModel):
    name = peewee.CharField()

class UserRoleThrough(BaseModel):
    user = peewee.ForeignKeyField(User, on_delete='CASCADE')
    role = peewee.ForeignKeyField(Role, on_delete='CASCADE')


if __name__ == '__main__':
    db = peewee.SqliteDatabase('test.db')
    db.pragma('foreign_keys', 1, permanent=True)
    db_proxy.initialize(db)

    tables = [
        User,
        Role,
        UserRoleThrough
    ]
    db.create_tables(tables)

    isaac = User.create(name='Isaac')
    admin = Role.create(name='Admin')
    UserRoleThrough.create(user=isaac, role=admin)
    User.delete().execute()

Answer 1

这已在 3.0.6 中修复：github.com/coleifer/peewee/blob/master/CHANGELOG.md#306

on_delete='CASCADE'好像没有效果

on_delete='CASCADE' seems to have no effect

python

peewee