Можете да използвате колекции на Oracles. CAST()
съчетано с COLLECT()
може да агрегира стойности в дефинирана от потребителя колекция и след това SET()
ще се отърве от дубликатите. След това можете да използвате LISTAGG()
за да конвертирате колекцията в низ.
Настройка на Oracle :
CREATE TYPE intlist IS TABLE OF INT;
/
CREATE TYPE stringlist IS TABLE OF VARCHAR2(4000);
/
CREATE TABLE table_name ( ColA NUMBER(5,0), ColB VARCHAR2(20) );
INSERT INTO table_name
SELECT 1, 'POW' FROM DUAL UNION ALL
SELECT 2, 'POW' FROM DUAL UNION ALL
SELECT 1, 'POWPRO' FROM DUAL UNION ALL
SELECT 1, 'PRO' FROM DUAL UNION ALL
SELECT 2, 'PRO' FROM DUAL UNION ALL
SELECT 1, 'PROUTL' FROM DUAL UNION ALL
SELECT 1, 'TNEUTL' FROM DUAL UNION ALL
SELECT 1, 'UTL' FROM DUAL UNION ALL
SELECT 1, 'UTLTNE' FROM DUAL;
Запитване :
SELECT ( SELECT LISTAGG( COLUMN_VALUE, ',' )
WITHIN GROUP ( ORDER BY COLUMN_VALUE )
FROM TABLE( ColA ) ) AS ColA,
( SELECT LISTAGG( COLUMN_VALUE, ',' )
WITHIN GROUP ( ORDER BY COLUMN_VALUE )
FROM TABLE( ColB ) ) AS ColB
FROM (
SELECT SET( CAST( COLLECT( ColA ORDER BY ColA ) AS INTLIST ) ) ColA,
SET( CAST( COLLECT( ColB ORDER BY ColB ) AS STRINGLIST ) ) ColB
FROM table_name
);
Изход :
ColA ColB
---- ---------------------------------------
1,2 POW,POWPRO,PRO,PROUTL,TNEUTL,UTL,UTLTNE