[英]How to call a parent method from a child via ForeignKeyField in peewee?
我有兩節課:
class A(Base_Model):
def ping(self):
print("Ping!")
class B(Base_Model):
__A_reference = peewee.ForeignKeyField(A, null=True)
def test_ping(self):
self.__A_reference.ping()
我初始化數據庫,創建兩個表並嘗試運行B.test_ping()
,但無濟於事。
嘗試更改我將外鍵指定為自引用的方式__A_reference = peewee.ForeignKeyField("self", null=True, backref="Bs")
,但再次沒有用。
試圖看一堆代碼示例,但似乎從來沒有這樣的情況:擁有外鍵的(子)對象實際上是在使用它從父對象中調用某些方法。
我不明白為什么這會造成混淆...訪問B .__ A_reference將返回相關的A實例:
In [1]: from peewee import *
In [2]: db = SqliteDatabase(':memory:')
In [3]: class A(Model):
...: def ping(self):
...: print('ping')
...: class Meta:
...: database = db
...:
In [4]: class B(Model):
...: a = ForeignKeyField(A)
...: class Meta:
...: database = db
...:
In [5]: db.create_tables([A, B])
In [6]: a = A.create()
In [7]: b = B.create(a=a)
In [8]: b.a.ping()
ping
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