SQLAlchemy 多对多
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)
Please call me JiangYouDang!