SqlAlchemy在没有外键的表上联接

Question

我在SqlAlchemy中有两个表

class T1(Record, SqlBase):
    __tablename__ = 'table1'
    __table_args__ = (PrimaryKeyConstraint('column'), {'autoload': True},)

class T2(Record, SqlBase):
    __tablename__ = 'table2'
    __table_args__ = (PrimaryKeyConstraint('column'), {'autoload': True},)

我想将两个表合并到某个公共列上

session.query(T1).join(session.query(T2), T1.column == T2.column)

但是我出错了

InvalidRequestError: Could not find a FROM clause to join from.  Tried joining to 
... but got: Can't find any foreign key relationships 
between 'T1' and 'FromGrouping object'. Perhaps you
 meant to convert the right side to a subquery using alias()?

我该如何解决这个问题？两个表中都没有外键

Answer 1

有用的文档

如果两个类有关系，您可以使用 join，或者您可以像这样编写没有 join 的查询

session.query(T1).filter(T1.column == T2.column)