mysql行列转换

myskya

原始插入数据如下：
$ B2 y" z" [# F$ ?+ j7 R, f2 d要求查询结果如下 ：

8 ]( e- U7 K* k# Q3 z7 p
创建数据库、表

1. create database tests;
   5 {5 f& Q* F- Q+ z; g" P
2. use tests;
   , I6 w4 s& G- b  I% l. ?- |/ ]
3. create table t_score(
   9 o, i6 z9 |0 v/ o0 w
4. id int primary key auto_increment,
   
5. name varchar(20) not null,  #名字
   ! Q. p' P8 Z' C* W5 e
6. Subject varchar(10) not null, #科目
   
7. Fraction double default 0  #分数
   
8. );

复制代码

添加数据

1. INSERT INTO `t_score`(name,Subject,Fraction) VALUES
   6 f& B4 S+ c$ Q1 A) A0 K
2.          ('王海', '语文', 86),
   7 p% p4 D8 |  ]% e& \) u( |! l
3.         ('王海', '数学', 83),
   % Q+ ]7 D, X, Z. I5 E
4.         ('王海', '英语', 93),
   
5.         ('陶俊', '语文', 88),
   * H4 }6 p3 t$ ?/ N" n: ]
6.         ('陶俊', '数学', 84),
   + R: h& W. r$ q: p& M2 l7 F% G
7.         ('陶俊', '英语', 94),
   
8.         ('刘可', '语文', 80),
   ; f+ _# \6 a" W$ I0 O
9.         ('刘可', '数学', 86),
   7 t: F" ?! ]9 @2 d! Q# s4 K
10.         ('刘可', '英语', 88),
    
11.         ('李春', '语文', 89),
    
12.         ('李春', '数学', 80),
    ) a& W2 x+ v7 A
13.         ('李春', '英语', 87);

复制代码

方式一:使用if

1. select name as 名字 ,
   
2. sum(if(Subject='语文',Fraction,0)) as 语文,
   4 G6 C: E. |) j0 W
3. sum(if(Subject='数学',Fraction,0))as 数学,
   
4. sum(if(Subject='英语',Fraction,0))as 英语,
   0 L( i/ |6 J: a" H
5. round(AVG(Fraction),2) as 平均分,
   ! c5 j) \- }, Q) n, F
6. SUM(Fraction) as 总分
   
7. from t_score group by name     
   
8. union
   / z: i/ o! W/ e$ \, M
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,
      {7 \2 I& W' l! r% }
11. sum(if(Subject='语文',Fraction,0)) as 语文,
    5 {5 A  {/ t$ p+ S8 F% f$ c
12. sum(if(Subject='数学',Fraction,0))as 数学,
    7 f& {0 H( ^+ ?8 C
13. sum(if(Subject='英语',Fraction,0))as 英语,
    
14. SUM(Fraction) as 总分
    9 I# Q! V" b2 \' O) F1 W$ p  B
15. from t_score group by Subject )t

复制代码

方式二:使用case

1. select  name as Name,
   
2. sum(case when Subject = '语文' then Fraction end) as Chinese,
   5 _! r5 c, l. Y! e: p; |7 ~6 Z
3. sum(case when Subject = '数学' then Fraction end) as Math,
   0 r2 ~+ W& h" J+ Q
4. sum(case when Subject = '英语' then Fraction end) as English,
   
5. sum(fraction)as score
   , v9 s% |- d0 Z* Z: k8 u8 g$ B
6. from t_score group by name
   
7. UNION ALL
   
8. select  name as Name,sum(Chinese) as Chinese,sum(Math) as Math,sum(English) as English,sum(score) as score from(
   % E7 U$ Y+ L( w8 U: t$ p; p
9. select 'TOTAL' as name,
   2 w4 D' H1 _( S$ c( w" ~/ ?
10. sum(case when Subject = '语文' then Fraction end) as Chinese,
    ) q9 A8 A$ s- q3 Y  h3 B
11. sum(case when Subject = '数学' then Fraction end) as Math,
    5 e) T0 T* ?% K5 f& W7 H/ G: i  N
12. sum(case when Subject = '英语' then Fraction end) as English,
    
13. sum(fraction)as score
    . {6 g; t9 s9 `) f+ M
14. from t_score group by Subject)t

复制代码

方法三: with rollup

1. select
   
2.         ifnull(name,'TOll') name,
   0 Y6 x2 [( I8 s+ k" n" a
3.         sum(if(Subject='语文',Fraction,0)) as 语文,
   8 _9 t/ n' ]) \
4.        sum(if(Subject='英语',Fraction,0)) as 英语,
   7 d/ ]/ l8 ?# N1 u
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

复制代码

查询结果如下：

  j" K" T8 x$ _* t% e7 |1 B
7 N7 R6 ?" u8 J* k. t- N( N$ r0 r