-- 插入测试数据 insert into User1(id,name,age) values( 1 , ' u1 ' , 1 ),( 2 , ' u2 ' , 2 ),( 2 , ' u2 ' , 222 ),( 3 , ' u3 ' , 3 ); insert into User2(id,name,age) values( 1 , ' u1 ' , 11 ),( 2 , ' u2 ' , 22 ),( 3 , ' u3 ' , 33 );

2.1 mysql 更新语句

update user1 a 
inner join user2 b on a.id=b.id
set a.age = b.age;

2.2 sql server 更新语句

update a set a.age=b.age
from User1 a
    inner join User2 b on a.id=b.id;

3 运行结果