Python中sqlalchemy update怎么使用

from sqlalchemy import create_engine, Table, Column, Integer, String
from sqlalchemy.orm import sessionmaker
from sqlalchemy import update
<h1>创建数据库引擎</h1><p>engine = create_engine("sqlite:///database.db")</p><h1>创建Session对象</h1><p>Session = sessionmaker(bind=engine)
session = Session()</p><h1>获取要更新的表</h1><p>users_table = Table("users", engine,
Column("id", Integer, primary_key=True),
Column("name", String(50)),
Column("email", String(50)))</p><h1>执行更新操作</h1><p>session.execute(
update(users_table).
where(users_table.c.id == 1).
values(name="John Doe")
)</p><h1>提交更改</h1><p>session.commit()

# 更新多个字段
session.execute(
update(users_table).
where(users_table.c.id == 1).
values(name="John Doe", email="johndoe@example.com")
)</p><h1>相对于现有值进行更新</h1><p>session.execute(
update(users_table).
where(users_table.c.id == 1).
values(age=users_table.c.age + 1)
)</p><h1>使用子查询进行更新</h1><p>subquery = session.query(users_table.c.age).filter(users_table.c.name == "Jane Doe")
session.execute(
update(users_table).
where(users_table.c.name == "John Doe").
values(age=subquery)
)</p><h1>批量更新</h1><p>session.execute(
update(users_table).
where(users<em>table.c.name.in</em>(["John Doe", "Jane Doe"])).
values(age=users_table.c.age + 1)
)