這是一道行轉列並且構造交叉表的問題：
http://topic.csdn.net/u/20090530/23/0b782674-4b0b-4cf5-bc1a-e8914aaee5ab.html
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
+------+-----+-----+-----+-----+------+
|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 |
+------+-----+-----+-----+-----+------+
1. 利用SUM(IF()) 生成列 + WITH ROLLUP 生成彙總行,並利用 IFNULL將彙總行標題顯示爲 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 生成彙總行,並利用 IFNULL將彙總行標題顯示爲
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，適用於列不確定情況，
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
可改寫爲
sum(case c2 when 'B1' then C3 else 0 end) AS B1