MySql行列转换方法自我总结

create table tx(
 id int primary key,
 c1 char(2),
 c2 char(2),
 money int,
 num int
);

insert into tx values
(1 ,'A1','B1',9,81),
(2 ,'A2','B1',7,53),
(3 ,'A3','B1',4,62),
(4 ,'A4','B1',2,91),
(5 ,'A1','B2',2,42),
(6 ,'A2','B2',9,66),
(7 ,'A3','B2',8,84),
(8 ,'A4','B2',5,55),
(9 ,'A1','B3',1,61),
(10 ,'A2','B3',8,43),
(11 ,'A3','B3',8,64),
(12 ,'A4','B3',6,72),
(13 ,'A1','B4',8,33),
(14 ,'A2','B4',2,24),
(15 ,'A3','B4',6,76),
(16 ,'A4','B4',9,51),
(17 ,'A1','B4',3,30),
(18 ,'A2','B4',5,26),
(19 ,'A3','B4',2,15),
(20 ,'A4','B4',5,11);

/*第一种静态列*/
 select ifnull(c1,'total'),
     sum(if(c2='B1',money,0)) AS B1money,
     sum(if(c2='B1',num,0)) AS B1num,
     sum(if(c2='B2',money,0)) AS B2money,
     sum(if(c2='B2',num,0)) AS B2num,
     sum(if(c2='B3',money,0)) AS B3money,
     sum(if(c2='B3',num,0)) AS B3num,
     sum(if(c2='B4',money,0)) AS B4money,
     sum(if(c2='B4',num,0)) AS B4num,
     SUM(money) AS TOTAL,
     SUM(num) AS TOTAL
     from tx
     group by c1 with rollup ;

/*第二种动态列*/

SET @EE='';

SELECT @EE:=CONCAT(
@EE,
'SUM(IF(C2=\'',C2,'\'',
',money,0)) AS ',
C2,
'money,',
'SUM(IF(C2=\'',C2,'\'',
',num,0)) AS ',
C2,
'num,') FROM (SELECT DISTINCT C2 FROM TX) A;

SET @QQ=CONCAT('SELECT ifnull(c1,\'total\'),',LEFT(@EE,LENGTH(@EE)-1),' ,SUM(money) AS moneyTOTAL,SUM(num) AS numTOTAL FROM

TX GROUP BY C1 WITH ROLLUP');

PREPARE stmt2 FROM @QQ;

EXECUTE stmt2;