sql条件查询语句实例

//创建成绩表
create table result(
       stu_id varchar2(20) not null,
       china number(9,2) null,
       math number(9,2) null,
       english number(9,2) null
);

//插入数据
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;

//条件查询
select  stu_id,(case 
         when china>





80 then '优秀' 
         when china>=60 then '及格' 
         when china<60 then  '不及格' 
         end) as 语文 ,
      (case 
         when math>80 then '优秀' 
         when math>=60 then '及格' 
         when math<60 then '不及格' 
       end )as 数学 ,
         (case 
         when english>80 then '优秀' 
         when english>=60 then '及格' 
         when english<60 then '不及格' 
       end) as 英语
from result