oracle decode 与case 的用法

好久不写SQL了，忘东西可真快。。。

select case
          when user like '%SM%' then 'SM7'
          when user like '%ADMIN%' then 'Admin'
          else 'not known'
      end as useraccount
from dual ;

select decode(user,'SM','SM7','not known') as useraccount
from dual;

原来忘了oracle中pl/sql case 与sql server的-sql case一样用法