一、表
from sqlalchemy.orm import relationship from sqlalchemy import Column from sqlalchemy import Integer,String class Depart(Base): __tablename__ = 'depart' id = Column(Integer, primary_key=True) title = Column(String(32), index=True, nullable=False) class Users(Base): __tablename__ = 'users' id = Column(Integer, primary_key=True) name = Column(String(32), index=True, nullable=False) depart_id = Column(Integer,ForeignKey("depart.id")) # dp 创建联系，不创建字段 dp = relationship("Depart", backref='pers')
二、数据操作
# 1. 查询所有用户+所属部门名称 ret = session.query(Users.id,Users.name,Depart.title).join(Depart,Users.depart_id == Depart.id).all() for row in ret: print(row.id,row.name,row.title) # left join, sql语句 query = session.query(Users.id,Users.name,Depart.title).join(Depart,Users.depart_id == Depart.id,isouter=True) print(query) # 2. relation字段:查询所有用户+所属部门名称 ====> 正向查询 推荐 ret = session.query(Users).all() for row in ret: print(row.id,row.name,row.depart_id,row.dp.title) # 3. relation字段:查询销售部所有的人员 =======> 反向查询 推荐 obj = session.query(Depart).filter(Depart.title == '销售').first() for row in obj.pers: print(row.id,row.name,obj.title) # 4. 创建一个名称叫：IT部门，再在该部门中添加一个员工：a # 方式一： d1 = Depart(title='IT') session.add(d1) session.commit() # u1 = Users(name='a',depart_id=d1.id) session.add(u1) session.commit() # 方式二：使用relation u1 = Users(name='a',dp=Depart(title='IT')) session.add(u1) session.commit() # 5. 创建一个名称叫：保洁的部门，再在该部门中添加多个员工：a/b/c d1 = Depart(title='保洁') d1.pers = [Users(name='a'),Users(name='b'),Users(name='c'),] session.add(d1) session.commit()
来源：博客园
作者：市丸银
链接：https://www.cnblogs.com/wt7018/p/11617825.html