Python ORM SQLAlchemy核心操作

SQLAlchemy ORM映射数据库表。declarative_base声明基类。Column/Integer/String列定义。Session事务会话。query查询。filter过滤。join关联。relationship关系映射。session.commit/rollback。惰性加载/eager加载。from sqlalchemy import create_engine, Column, Integer, String, ForeignKeyfrom sqlalchemy.orm import declarative_base, Session, relationshipBase declarative_base()engine create_engine(sqlite:///example.db, echoTrue)class User(Base):__tablename__ usersid Column(Integer, primary_keyTrue)name Column(String)age Column(Integer)addresses relationship(Address, back_populatesuser)class Address(Base):__tablename__ addressesid Column(Integer, primary_keyTrue)email Column(String)user_id Column(Integer, ForeignKey(users.id))user relationship(User, back_populatesaddresses)Base.metadata.create_all(engine)with Session(engine) as session:user User(nameAlice, age30)session.add(user)session.commit()users session.query(User).filter(User.age 25).all()for u in users:print(u.name, u.age)