擅长:python、mysql、java
<p>X.x2y。property.mapper.class\在</p>
<p>relationshipproperty最终将获得类级别的属性文档,就像mapper现在所做的那样。在</p>
<p>编辑。下面是一个测试,它演示了上面从“X”返回“Y”的过程,没有反射不会创建关系,因此应该没有任何效果:</p>
<pre><code>from sqlalchemy import Column, Integer, ForeignKey
from sqlalchemy.orm import relationship
from sqlalchemy.ext.declarative import declarative_base
Base = declarative_base()
class X(Base):
__tablename__ = 'x'
id = Column(Integer, primary_key=True)
x2y = relationship("Y")
class Y(Base):
__tablename__ = 'y'
id = Column(Integer, primary_key=True)
x_id = Column(Integer, ForeignKey("x.id"))
assert X.x2y.property.mapper.class_ is Y
</code></pre>