应用场景：

表a为主表，表b为备份表，当表a的数据出现问题，需要根据表b的数据进行回滚

sql：

update test a inner join (select
 b.id,
 c.name,
 c.address
 from test b left join test_tmp c on b.id = c.id) d on a.id = d.id 
 set 
 a.address = d.address,
 a.name = d.name;