按如下要求写出sql语句:
-- 1
update user2
set ename='William'
where userid='102'
-- 2
update user2
set credit=credit +50
where city='北京'
-- 3
update user2
set credit=credit +100
where name in (select name from user2 where substring(personId,7,4)<'1991')
-- 4
update transinfo2
set remark='发薪水'
where remark='工资'
-- 5
update card2
set money=money*1.01
where true;
-- 6
update card2
set password=reverse(`password`)
where true;