mysql行列转换

myskya

原始插入数据如下：
要求查询结果如下 ：


创建数据库、表

1. create database tests;
   
2. use tests;
   
3. create table t_score(
     a1 Y& m, O/ S8 S& Q
4. id int primary key auto_increment,
   . x  G1 l! c# I4 n. B9 H! j
5. name varchar(20) not null,  #名字
   4 D& V. s3 ^1 f) U
6. Subject varchar(10) not null, #科目
     g$ @9 e9 ~. @
7. Fraction double default 0  #分数
   ; Y" C* ^/ q2 E% i# S) a9 |
8. );

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添加数据

1. INSERT INTO `t_score`(name,Subject,Fraction) VALUES
     G5 A' u/ e) B9 y
2.          ('王海', '语文', 86),
   
3.         ('王海', '数学', 83),
   8 ~/ T% a- z/ Y1 @6 ]5 n# d
4.         ('王海', '英语', 93),
   % E) J# U( o8 C0 n
5.         ('陶俊', '语文', 88),
   , [! ?" [% \* B
6.         ('陶俊', '数学', 84),
   3 l0 O" o) U8 Q
7.         ('陶俊', '英语', 94),
   
8.         ('刘可', '语文', 80),
   % _5 U/ J9 ^! Z# \% z& A4 E% @; X
9.         ('刘可', '数学', 86),
   
10.         ('刘可', '英语', 88),
    
11.         ('李春', '语文', 89),
    
12.         ('李春', '数学', 80),
    * }- d) U- [* a5 N
13.         ('李春', '英语', 87);

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方式一:使用if

1. select name as 名字 ,
   
2. sum(if(Subject='语文',Fraction,0)) as 语文,
   
3. sum(if(Subject='数学',Fraction,0))as 数学,
   
4. sum(if(Subject='英语',Fraction,0))as 英语,
   0 x1 K& y# f% c0 f
5. round(AVG(Fraction),2) as 平均分,
   5 @$ y# g; y) o, [. x# Y. T
6. SUM(Fraction) as 总分
   
7. from t_score group by name     
   
8. union
   # c0 k* N2 q7 M; P. m6 J
9. select name as 名字 , sum(语文) Chinese,sum(数学) Math,sum(英语) English,round(AVG(总分),2)as 平均分,sum(总分) score  from(
   
10. select 'TOTAL' as name,
    
11. sum(if(Subject='语文',Fraction,0)) as 语文,
    8 b  l, P, @4 b
12. sum(if(Subject='数学',Fraction,0))as 数学,
    + S- ]3 \$ m; y& X  c
13. sum(if(Subject='英语',Fraction,0))as 英语,
    $ e1 B. m& L/ v7 S
14. SUM(Fraction) as 总分
    
15. from t_score group by Subject )t

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方式二:使用case

1. select  name as Name,
   6 W5 a/ L0 Y6 R/ Y( w
2. sum(case when Subject = '语文' then Fraction end) as Chinese,
   . _* x; M2 M3 j6 E, O+ ~
3. sum(case when Subject = '数学' then Fraction end) as Math,
   3 q, n; B1 }3 G6 o% B
4. sum(case when Subject = '英语' then Fraction end) as English,
   7 H, Y- J3 X* C2 O' ]- I6 X
5. sum(fraction)as score
   ) [% q1 v, k, {/ _) r( S
6. from t_score group by name
   5 f; _  m: i4 @6 J" ]6 A* z7 r) Q
7. UNION ALL
   4 o0 O3 G2 }7 t" ]
8. select  name as Name,sum(Chinese) as Chinese,sum(Math) as Math,sum(English) as English,sum(score) as score from(
   ! H3 D9 M6 }: \$ E8 X
9. select 'TOTAL' as name,
   * M$ d. U. v# g" [# l& w
10. sum(case when Subject = '语文' then Fraction end) as Chinese,
    
11. sum(case when Subject = '数学' then Fraction end) as Math,
    
12. sum(case when Subject = '英语' then Fraction end) as English,
    $ r/ H7 ~6 K  R, P5 u& |
13. sum(fraction)as score
    # T) I" ]8 u, o& h
14. from t_score group by Subject)t

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方法三: with rollup

1. select
   0 ^- U6 x1 C5 t" ^2 f
2.         ifnull(name,'TOll') name,
   
3.         sum(if(Subject='语文',Fraction,0)) as 语文,
   # s# q4 h* K$ n2 j& O9 k+ c
4.        sum(if(Subject='英语',Fraction,0)) as 英语,
   " \: q: D& T1 C+ y) L
5.        sum(if(Subject='数学',Fraction,0))as 数学,
   
6.        sum(Fraction) 总分
   
7.         from t_score group by name with rollup

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查询结果如下：

& E' W4 I1 Q3 k2 S) C6 Y, }