Oracle行列转换问题

今天又有朋友讨论以下行列转换问题:

编码 行 值

AA 　1 345

BB 　1 456

CC 　1 657

DD 　2 546

EE 　2 434

FF 　2 897

GG 　3 566 要实现如下转换

1 2 3

AA345 DD546 GG566

BB456 EE434

CC657 FD897

关键点是行1,2，3有若干个，不是固定是3个。。

create table test (a1 varchar2(10), a2 number(3), a3 varchar2(6));

insert into test values('AA',1,'345');

insert into test values('BB',1,'456');

insert into test values('CC',1,'657');

insert into test values('DD',2,'546');

insert into test values('EE',2,'434');

insert into test values('FF',2,'897');

insert into test values('GG',3,'566');

insert into test values('EE',1,'457');

commit;

SQL> select * from test;

A1 A2 A3

---------- ---------- ------

AA 1 345

BB 1 456

CC 1 657

DD 2 546

EE 2 434

FF 2 897

GG 3 566

EE 1 457

with atest as

(

select icol*10+irow icol,irow, decode(icol,1,ivalue) c1 ,decode(icol,2,ivalue) c2, decode(icol,3,ivalue) c3

from (

select a2 icol, a1||a3 ivalue, row_number() [b]over(partition by[/b] a2 order by a1||a3) irow from test)

)

select irow , ltrim(rtrim(max(sys_connect_by_path(c1,' ')))) c1,

ltrim(rtrim(max(sys_connect_by_path(c2,' ')))) c2,

ltrim(rtrim(max(sys_connect_by_path(c3,' ')))) c3 from atest

connect by icol-10 = prior icol

group by irow

SQL> col c1 for a10;

SQL> col c2 for a10;

SQL> col c3 for a10;

SQL> select irow , ltrim(rtrim(max(sys_connect_by_path(c1,' ')))) c1,

2 ltrim(rtrim(max(sys_connect_by_path(c2,' ')))) c2,

3 ltrim(rtrim(max(sys_connect_by_path(c3,' ')))) c3 from

4 (

5 select icol*10+irow icol,irow, decode(icol,1,ivalue) c1 ,decode(icol,2,ivalue) c2, decode(icol,3,ivalue) c3

6 from (

7 select a2 icol, a1||a3 ivalue, row_number() over(partition by a2 order by a1||a3) irow from test)

8 )

9 connect by icol-10 = prior icol

10 group by irow

11 ;

IROW C1 C2 C3

---------- ---------- ---------- ----------

1 AA345 DD546 GG566

2 BB456 EE434

3 CC657 FF897

4 EE457

Oracle10g 中, 还有函数 WMSYS.WM_CONCAT 可以使用, 如

SQL> WITH A AS (

2 SELECT 1123 ID,'2008-9-19' DAY,'9:7:47' TIME FROM DUAL UNION

3 SELECT 1123 ID,'2008-9-19' DAY,'19:7:47' TIME FROM DUAL UNION

4 SELECT 1123 ID,'2008-9-29' DAY,'13:7:47' TIME FROM DUAL UNION

5 SELECT 1123 ID,'2008-9-29' DAY,'12:7:47' TIME FROM DUAL )

6 select ID,DAY,WMSYS.WM_CONCAT(TIME) TIME FROM A GROUP BY ID,DAY;

ID DAY TIME

---------- --------- --------------------

1123 2008-9-19 19:7:47,9:7:47

1123 2008-9-29 12:7:47,13:7:47