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SQLAlchemy 多对多

时间:2021-07-26 16:48:08      阅读:0      评论:0      收藏:0      [点我收藏+]

标签:column   comm   figure   base   maker   metadata   ack   second   temp   

参考官网: https://www.pythoncentral.io/sqlalchemy-orm-examples/  

员工部门两个表,中间为多对多关系,这种一般需要创建一个中间表。多对多转换成一对多

from sqlalchemy import Integer, Column, String, ForeignKey
from sqlalchemy.orm import declarative_base, relationship, backref, sessionmaker
from sqlalchemy import create_engine

Base = declarative_base()


class Department(Base):
    __tablename__ = department
    id = Column(Integer, primary_key=True)
    name = Column(String)
    employees = relationship(Employee, secondary=department_employee)


class Employee(Base):
    __tablename__ = employee
    id = Column(Integer, primary_key=True)
    name = Column(String)
    departments = relationship(Department, secondary=department_employee)


class DepartmentEmployee(Base):
    __tablename__ = department_employee
    department_id = Column(Integer, ForeignKey(department.id), primary_key=True)
    employee_id = Column(Integer, ForeignKey(employee.id), primary_key=True)


engine = create_engine("sqlite:///")
session = sessionmaker()
session.configure(bind=engine)
Base.metadata.create_all(engine)

s = session()
john = Employee(name=Jhon)
s.add(john)
it_department = Department(name=IT)
it_department.employees.append(john)
s.add(it_department)
s.commit()
johnDB = s.query(Employee).filter(Employee.name == Jhon).one()
print(johnDB.name)
print(johnDB.departments[0].name)

 

SQLAlchemy 多对多

标签:column   comm   figure   base   maker   metadata   ack   second   temp   

原文地址:https://www.cnblogs.com/luckygxf/p/15057503.html

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