Oracle列转行函数Listagg以及pivot查询示例

简单的Oracle列转行函数Listagg示例：

CREATE TABLE tbl_test
(catalog VARCHAR(1),product VARCHAR(2),amount NUMBER);

INSERT INTO tbl_test VALUES('A','A1',1);
INSERT INTO tbl_test VALUES('A','A1',2);
INSERT INTO tbl_test VALUES('B','B1',3);
INSERT INTO tbl_test VALUES('B','B2',4);
INSERT INTO tbl_test VALUES('B','B2',5);
INSERT INTO tbl_test VALUES('C','C1',6);
INSERT INTO tbl_test VALUES('C','C1',7);
INSERT INTO tbl_test VALUES('C','C2',8);
INSERT INTO tbl_test VALUES('C','C2',9);
COMMIT;

SELECT * FROM tbl_test;

CATALOG PRODUCT     AMOUNT
------- ------- ----------
A       A1               1
A       A1               2
B       B1               3
B       B2               4
B       B2               5
C       C1               6
C       C1               7
C       C2               8
C       C2               9 

 9 rows selected

SELECT
LISTAGG(product,',') WITHIN GROUP( ORDER BY amount) AS lst
FROM tbl_test;

LST
----------------------------
A1,A1,B1,B2,B2,C1,C1,C2,C2 

SELECT
catalog, LISTAGG(product,',') WITHIN GROUP( ORDER BY amount) as lst
FROM tbl_test
GROUP BY catalog;

CATALOG LST
------- -----------------
A       A1,A1
B       B1,B2,B2
C       C1,C1,C2,C2  

SELECT
LISTAGG(product||'-'||amount,',') WITHIN GROUP( ORDER BY amount) over (partition by catalog)
AS lst
FROM tbl_test
;

LST
----------------------
A1-1,A1-2
A1-1,A1-2
B1-3,B2-4,B2-5
B1-3,B2-4,B2-5
B1-3,B2-4,B2-5
C1-6,C1-7,C2-8,C2-9
C1-6,C1-7,C2-8,C2-9
C1-6,C1-7,C2-8,C2-9
C1-6,C1-7,C2-8,C2-9  

 9 rows selected 

SELECT * FROM tbl_test
pivot (
       sum(amount)
			 FOR(catalog)
			 IN('A','B','C')
)
ORDER BY 1;

PRODUCT        'A'        'B'        'C'
------- ---------- ---------- ----------
A1               3
B1                          3
B2                          9
C1                                    13
C2                                    17 

SELECT product,EXTRACT(catalog_xml,'//column[@name="SUM(AMOUNT)"]/text()') AS sum
FROM tbl_test
pivot xml(
       sum(amount)
			 FOR(catalog)
			 IN(ANY)
)
ORDER BY 1;

PRODUCT SUM
------- -------
A1      3
B1      3
B2      9
C1      13
C2      17