MySQL批量更新的四种方式总结

replace into `user` (id,age) values (1,'2'),(2,'3'),(3,'4'),(4,'98');
-- > 时间: 0.038s

insert into `user`(id,age) values (1,'5'),(2,'7'),(3,'2'),(4,'198') on duplicate key update age=values(age)
-- > > 时间: 0.017s

DROP TABLE if EXISTS tmp;
-- > 时间: 0.016s

create temporary table tmp(id int(4) primary key,age varchar(50));
-- > 时间: 0.01s

insert into tmp values  (1,'13'), (2,'16'),(3,'18'),(4,'18');
-- > 时间: 0.009s

update `user`, tmp set `user`.age=tmp.age where `user`.id=tmp.id;
-- > 时间: 0.022s

update `user`
	set age = CASE id
	WHEN 1 THEN '22'
	WHEN 2 THEN '22'
	WHEN 3 THEN '22'
	WHEN 4 THEN '22'
END WHERE id IN(1,2,3,4);
-- > 时间: 0.015s

update (表名)
set (更新字段) = case (被更新字段)
when (被更新字段值) then (更新字段值)...
end where (被更新字段) in((被更新字段值)...)