我有用户和实体(多对多),并使用 sqlalchemy,这个模型:
from sqlalchemy import Table, Column, Unicode, Integer, ForeignKey
from sqlalchemy.orm import relationship
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import scoped_session, sessionmaker
from zope.sqlalchemy import ZopeTransactionExtension
DBSession = scoped_session(sessionmaker(extension=ZopeTransactionExtension()))
Base = declarative_base()
users_entities = Table('users_entities', Base.metadata,
Column('userID', Integer, ForeignKey('users.id')),
Column('entitieID', Integer, ForeignKey('entities.id'))
)
class User(Base):
__tablename__ = 'users'
id = Column(Integer, primary_key=True)
username = Column(Unicode(20))
password = Column(Unicode(101))
entities = relationship("Entities", secondary=users_entities)
def __init__(self, username, password):
self.username = username
self.password = password
class Entities(Base):
__tablename__ = 'entities'
id = Column(Integer, primary_key=True)
name = Column(Unicode(20))
descr = Column(Unicode(101))
url = Column(Unicode(101))
def __init__(self, name, descr, url):
self.name = name
self.descr = descr
self.url = url
所以,当我使用:
user = dbsession.query(User).filter_by(id=session["userID"]).first()
entities = user.entities
我得到了user
用户数据,以及所有用户实体的entities
( )。user.entities
但是现在我需要从 id 为 = X 的用户那里获取一个实体,而不是获取所有实体,这将像这样工作:
user.query(Entities).filter_by(id=X)
我找不到简单(“最佳”)的方法来做到这一点,我错过了什么吗?