//創建成績表
create table result(
       stu_id varchar2(20) not null,
       china number(9,2) null,
       math number(9,2) null,
       english number(9,2) null
);

//插入數據
insert into result values('0001',60,20,80);
insert into result values('0002',80,60,80);
insert into result values('0003',20,85,80);
select *from result;

//條件查詢
select  stu_id,(case
         when china>80 then '優秀'
         when china>=60 then '及格'
         when china<60 then  '不及格'
         end) as 語文 ,
      (case
         when math>80 then '優秀'
         when math>=60 then '及格'
         when math<60 then '不及格'
       end )as 數學 ,
         (case
         when english>80 then '優秀'
         when english>=60 then '及格'
         when english<60 then '不及格'
       end) as 英語
from result