數據樣本：

create table

tx(

id int primary key,

c1 char(2),

c2 char(2),

c3 int

);

insert into tx

values

(1 ,'A1','B1',9),

(2 ,'A2','B1',7),

(3 ,'A3','B1',4),

(4 ,'A4','B1',2),

(5 ,'A1','B2',2),

(6 ,'A2','B2',9),

(7 ,'A3','B2',8),

(8 ,'A4','B2',5),

(9 ,'A1','B3',1),

(10 ,'A2','B3',8),

(11 ,'A3','B3',8),

(12 ,'A4','B3',6),

(13 ,'A1','B4',8),

(14 ,'A2','B4',2),

(15 ,'A3','B4',6),

(16 ,'A4','B4',9),

(17 ,'A1','B4',3),

(18 ,'A2','B4',5),

(19 ,'A3','B4',2),

(20 ,'A4','B4',5);

mysql> select * from tx;

+----+------+------+------+

| id | c1?|

c2?|

c3?|

+----+------+------+------+

|?1 | A1?|

B1?|?9 |

|?2 | A2?|

B1?|?7 |

|?3 | A3?|

B1?|?4 |

|?4 | A4?|

B1?|?2 |

|?5 | A1?|

B2?|?2 |

|?6 | A2?|

B2?|?9 |

|?7 | A3?|

B2?|?8 |

|?8 | A4?|

B2?|?5 |

|?9 | A1?|

B3?|?1 |

| 10 | A2?|

B3?|?8 |

| 11 | A3?|

B3?|?8 |

| 12 | A4?|

B3?|?6 |

| 13 | A1?|

B4?|?8 |

| 14 | A2?|

B4?|?2 |

| 15 | A3?|

B4?|?6 |

| 16 | A4?|

B4?|?9 |

| 17 | A1?|

B4?|?3 |

| 18 | A2?|

B4?|?5 |

| 19 | A3?|

B4?|?2 |

| 20 | A4?|

B4?|?5 |

+----+------+------+------+

20 rows in set (0.00 sec)

mysql>

期望結果

+------+-----+-----+-----+-----+------+

|C1?|B1?|B2?|B3?|B4?|Total |

+------+-----+-----+-----+-----+------+

|A1?|9?|2?|1?|11?|23?|

|A2?|7?|9?|8?|7?|31?|

|A3?|4?|8?|8?|8?|28?|

|A4?|2?|5?|6?|14?|27?|

|Total |22?|24?|23?|40?|109?|

+------+-----+-----+-----+-----+------+

1. 利用SUM(IF()) 生成列 + WITH ROLLUP 生成匯總行,并利用

IFNULL將匯總行標題顯示為 Total

mysql>

SELECT

IFNULL(c1,'total') AS total,

SUM(IF(c2='B1',c3,0)) AS B1,

SUM(IF(c2='B2',c3,0)) AS B2,

SUM(IF(c2='B3',c3,0)) AS B3,

SUM(IF(c2='B4',c3,0)) AS B4,

SUM(IF(c2='total',c3,0)) AS total

FROM (

SELECT c1,IFNULL(c2,'total') AS c2,SUM(c3) AS c3

FROM tx?GROUP BY c1,c2

WITH ROLLUP?HAVING c1 IS NOT NULL

) AS A

GROUP BY c1

WITH ROLLUP;

+-------+------+------+------+------+-------+

| total | B1?|

B2?|

B3?|

B4?| total |

+-------+------+------+------+------+-------+

| A1?|?9

|?2

|?1

|?11

|?23 |

| A2?|?7

|?9

|?8

|?7

|?31 |

| A3?|?4

|?8

|?8

|?8

|?28 |

| A4?|?2

|?5

|?6

|?14

|?27 |

| total |?22

|?24

|?23

|?40

|?109 |

+-------+------+------+------+------+-------+

5 rows in set, 1 warning (0.00 sec)

2. 利用SUM(IF()) 生成列 + UNION 生成匯總行,并利用 IFNULL將匯總行標題顯示為

Total

mysql>

select c1,

sum(if(c2='B1',C3,0)) AS B1,

sum(if(c2='B2',C3,0)) AS B2,

sum(if(c2='B3',C3,0)) AS B3,

sum(if(c2='B4',C3,0)) AS B4,SUM(C3) AS TOTAL

from tx

group by C1

UNION

SELECT 'TOTAL',sum(if(c2='B1',C3,0)) AS B1,

sum(if(c2='B2',C3,0)) AS B2,

sum(if(c2='B3',C3,0)) AS B3,

sum(if(c2='B4',C3,0)) AS B4,SUM(C3) FROM

TX;

+-------+------+------+------+------+-------+

| c1?|

B1?|

B2?|

B3?|

B4?| TOTAL |

+-------+------+------+------+------+-------+

| A1?|?9

|?2

|?1

|?11

|?23 |

| A2?|?7

|?9

|?8

|?7

|?31 |

| A3?|?4

|?8

|?8

|?8

|?28 |

| A4?|?2

|?5

|?6

|?14

|?27 |

| TOTAL |?22

|?24

|?23

|?40

|?109 |

+-------+------+------+------+------+-------+

5 rows in set (0.00 sec)

mysql>

3.?利用SUM(IF())

生成列,直接生成結果不再利用子查詢

mysql>

select

ifnull(c1,'total'),

sum(if(c2='B1',C3,0)) AS B1,

sum(if(c2='B2',C3,0)) AS B2,

sum(if(c2='B3',C3,0)) AS B3,

sum(if(c2='B4',C3,0)) AS B4,SUM(C3) AS TOTAL

from tx

group by C1 with rollup ;

+--------------------+------+------+------+------+-------+

| ifnull(c1,'total') | B1?|

B2?|

B3?|

B4?| TOTAL |

+--------------------+------+------+------+------+-------+

|

A1?|?9

|?2

|?1

|?11

|?23 |

|

A2?|?7

|?9

|?8

|?7

|?31 |

|

A3?|?4

|?8

|?8

|?8

|?28 |

|

A4?|?2

|?5

|?6

|?14

|?27 |

|

total?|?22

|?24

|?23

|?40

|?109 |

+--------------------+------+------+------+------+-------+

5 rows in set (0.00 sec)

mysql>

4. 動態，適用于列不確定情況，

mysql> SET @EE='';

mysql> SELECT

@EE:=CONCAT(@EE,'SUM(IF(C2='',C2,''',',C3,0)) AS ',C2,',') FROM

(SELECT DISTINCT C2 FROM TX) A;

mysql> SET @QQ=CONCAT('SELECT

ifnull(c1,'total'),',LEFT(@EE,LENGTH(@EE)-1),' ,SUM(C3) AS TOTAL

FROM TX GROUP BY C1 WITH ROLLUP');

Query OK, 0 rows affected (0.00 sec)

mysql> PREPARE stmt2 FROM @QQ;

Query OK, 0 rows affected (0.00 sec)

Statement prepared

mysql> EXECUTE stmt2;

+--------------------+------+------+------+------+-------+

| ifnull(c1,'total') | B1?|

B2?|

B3?|

B4?| TOTAL |

+--------------------+------+------+------+------+-------+

|

A1?|?9

|?2

|?1

|?11

|?23 |

|

A2?|?7

|?9

|?8

|?7

|?31 |

|

A3?|?4

|?8

|?8

|?8

|?28 |

|

A4?|?2

|?5

|?6

|?14

|?27 |

|

total?|?22

|?24

|?23

|?40

|?109 |

+--------------------+------+------+------+------+-------+

5 rows in set (0.00 sec)

mysql>

其實數據庫中也可以用 CASE WHEN /

DECODE?代替 IF

sum(if(c2='B1',C3,0)) AS B1

可改寫為

sum(case c2 when 'B1' then C3 else 0 end) AS B1

總結

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