所有數學課程成績 大於 語文課程成績的學生的學號
所有數學課程成績 大於 語文課程成績的學生的學號
CREATE TABLE course
(id
int,sid
int ,course
string,score
int
) ;
// 插入資料
// 欄位解釋:id, 學號, 課程, 成績
INSERT INTO course
VALUES (1, 1, 'yuwen', 43);
INSERT INTO course
VALUES (2, 1, 'shuxue', 55);
INSERT INTO course
VALUES (3, 2, 'yuwen', 77);
INSERT INTO course
VALUES (4, 2, 'shuxue', 88);
INSERT INTO course
INSERT INTO
course
VALUES (6, 3, 'shuxue', 65);
求:所有數學課程成績 大於 語文課程成績的學生的學號
select sid,case when course="yuwen" then score else 0 end as yuwen,
case when course="shuxue" then score else 0 end as shuxue
from course;
1 43 0
1 0 55
2 77 0
2 0 88
3 98 0
3 0 65
select tmp.sid,Max(tmp.yuwen) as yuwen,max(tmp.shuxue) as shuxue
from(
select sid,case when course="yuwen" then score else 0 end as yuwen,
case when course="shuxue" then score else 0 end as shuxue
from course
) tmp
group by tmp.sid;
1 43 55
2 77 88
3 98 65
select stmp.sid
from (
select tmp.sid,Max(tmp.yuwen) as yuwen,max(tmp.shuxue) as shuxue
from(
select sid,case when course="yuwen" then score else 0 end as yuwen,
case when course="shuxue" then score else 0 end as shuxue
from course
) tmp
group by tmp.sid
) stmp where stmp.shuxue > stmp.yuwen;