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HomeDatabaseMysql TutorialOracle 行转列 的写法

Oracle 行转列 的写法: /* DROP TABLE FOO; */ /**创建一张演示的表**/ CREATE TABLE FOO ( BBBID NUMBER(2), --主键

Oracle 行转列 的写法:

/*

DROP TABLE FOO;

*/

/**创建一张演示的表**/

CREATE TABLE FOO (

    BBBID NUMBER(2),       --主键

    DEPID NUMBER(2),      --单位编号

    AAC006 VARCHAR2(1)  --性别  1男  2女  0未知

    CONSTRAINT CK_AAC006 CHECK (AAC006 = '1' OR AAC006 ='2' OR AAC006 ='0')

);

/**插入用于测试的数据**/

INSERT INTO FOO VALUES(1,1,'1');

INSERT INTO FOO VALUES(2,1,'0');

INSERT INTO FOO VALUES(3,1,'2');

INSERT INTO FOO VALUES(4,1,'2');

INSERT INTO FOO VALUES(5,2,'1');

INSERT INTO FOO VALUES(6,2,'0');

INSERT INTO FOO VALUES(7,2,'2');

INSERT INTO FOO VALUES(8,2,'2');

INSERT INTO FOO VALUES(9,3,'2');

INSERT INTO FOO VALUES(10,3,'2');

INSERT INTO FOO VALUES(11,3,'2');

/**

目标:对该表进行行转列,要得到如下结果集:

depid 男 女 未知

 1  2

 1  2

 0  3

*/

/**原始的数据**/

SELECT * FROM FOO;

/**按照性别码表取值,将FOO.AAC006转化为3列之后的值**/

SELECT DEPID,

    DECODE(AAC006,'0',1,0) "男",

    DECODE(AAC006,'1',1,0) "女",

    DECODE(AAC006,'2',1,0) "未知"

 FROM  FOO;

 /**在上一个结果集上进行加工,就得到行转列的结果!**/

 SELECT DEPID,

    SUM(DECODE(AAC006,'0',1,0)) "男",

    SUM(DECODE(AAC006,'1',1,0)) "女",

    SUM(DECODE(AAC006,'2',1,0)) "未知"

 FROM  FOO

 GROUP BY DEPID;


 /**

 总结(czw  20120624):

 行转列,,其实就是将某一个字段,按照码值拆分为若干个字段,最后通过聚集函数得到相应的值。

 **/

linux

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