- ：
感谢朋友支持本博客，欢迎共同探讨交流，由于能力和时间有限，错误之处在所难免，欢迎指正！
如有转载，请保留源作者博客信息。
如需交流，欢迎大家博客留言。
- #简单查询
- print(session.query(User).all())
- print(session.query(User.name, User.fullname).all())
- print(session.query(User, User.name).all())
- #带条件查询
- print(session.query(User).filter_by(name='user1').all())
- print(session.query(User).filter(User.name == "user").all())
- print(session.query(User).filter(User.name.like("user%")).all())
- #多条件查询
- print(session.query(User).filter(and_(User.name.like("user%"), User.fullname.like("first%"))).all())
- print(session.query(User).filter(or_(User.name.like("user%"), User.password != None)).all())
- #sql过滤
- print(session.query(User).filter("id>:id").params(id=1).all())
- #关联查询
- print(session.query(User, Address).filter(User.id == Address.user_id).all())
- print(session.query(User).join(User.addresses).all())
- print(session.query(User).outerjoin(User.addresses).all())
- #聚合查询
- print(session.query(User.name, func.count('*').label("user_count")).group_by(User.name).all())
- print(session.query(User.name, func.sum(User.id).label("user_id_sum")).group_by(User.name).all())
- #子查询
- stmt = session.query(Address.user_id, func.count('*').label("address_count")).group_by(Address.user_id).subquery()
- print(session.query(User, stmt.c.address_count).outerjoin((stmt, User.id == stmt.c.user_id)).order_by(User.id).all())
- #exists
- print(session.query(User).filter(exists().where(Address.user_id == User.id)))
- print(session.query(User).filter(User.addresses.any()))
以下为映射类：
- class User(Base):
- __tablename__ = "users"
- id = Column("id", Integer, primary_key=True)
- name = Column("name", String)
- fullname = Column("fullname", String)
- password = Column("password", String)
- addresses = relation("Address", order_by="Address.id", backref="user")
- def __init__(self, id=None, name=None, fullname=None, password=None, addresses=[]):
- self.id = id
- self.name = name
- self.fullname = fullname
- self.password = password
- self.addresses = addresses
- def __repr__(self):
- return "<User '{name}' '{fullname}' '{password}' {addresses}>".format(name=self.name, fullname=self.fullname, password=self.password, addresses=self.addresses)
- class Address(Base):
- __tablename__ = "address"
- id = Column(Integer, primary_key=True)
- email_address = Column(String, nullable=False)
- user_id = Column(Integer, ForeignKey("users.id"))
- #user = relation("User", backref="addresses", order_by="Address.id")
- def __init__(self, email_address=None):
- self.email_address = email_address
- def __repr__(self):
- return "<Address ({email_address}) user={user}>".format(email_address=self.email_address, user=self.user.name)