Angepasst von meiner Antwort zu einer anderen Frage.
Oracle-Setup :
CREATE OR REPLACE TYPE VARCHAR2s_Table IS TABLE OF VARCHAR2(100);
/
Erstellen Sie einen benutzerdefinierten Aggregationstyp:
CREATE OR REPLACE TYPE Varchar2sTableUnion AS OBJECT(
list VARCHAR2s_Table,
STATIC FUNCTION ODCIAggregateInitialize(
ctx IN OUT Varchar2sTableUnion
) RETURN NUMBER,
MEMBER FUNCTION ODCIAggregateIterate(
self IN OUT Varchar2sTableUnion,
value IN VARCHAR2s_Table
) RETURN NUMBER,
MEMBER FUNCTION ODCIAggregateTerminate(
self IN OUT Varchar2sTableUnion,
returnValue OUT VARCHAR2s_Table,
flags IN NUMBER
) RETURN NUMBER,
MEMBER FUNCTION ODCIAggregateMerge(
self IN OUT Varchar2sTableUnion,
ctx IN OUT Varchar2sTableUnion
) RETURN NUMBER
);
/
CREATE OR REPLACE TYPE BODY Varchar2sTableUnion
IS
STATIC FUNCTION ODCIAggregateInitialize(
ctx IN OUT Varchar2sTableUnion
) RETURN NUMBER
IS
BEGIN
ctx := Varchar2sTableUnion( NULL );
RETURN ODCIConst.SUCCESS;
END;
MEMBER FUNCTION ODCIAggregateIterate(
self IN OUT Varchar2sTableUnion,
value IN VARCHAR2s_Table
) RETURN NUMBER
IS
BEGIN
IF value IS NULL THEN
NULL;
ELSIF self.list IS NULL THEN
self.list := value;
ELSE
self.list := self.list MULTISET UNION DISTINCT value;
END IF;
RETURN ODCIConst.SUCCESS;
END;
MEMBER FUNCTION ODCIAggregateTerminate(
self IN OUT Varchar2sTableUnion,
returnValue OUT VARCHAR2s_Table,
flags IN NUMBER
) RETURN NUMBER
IS
BEGIN
returnValue := self.list;
RETURN ODCIConst.SUCCESS;
END;
MEMBER FUNCTION ODCIAggregateMerge(
self IN OUT Varchar2sTableUnion,
ctx IN OUT Varchar2sTableUnion
) RETURN NUMBER
IS
BEGIN
IF self.list IS NULL THEN
self.list := ctx.list;
ELSIF ctx.list IS NULL THEN
NULL;
ELSE
self.list := self.list MULTISET UNION DISTINCT ctx.list;
END IF;
RETURN ODCIConst.SUCCESS;
END;
END;
/
Erstellen Sie eine benutzerdefinierte Aggregationsfunktion:
CREATE FUNCTION MULTISET_UNION( list VARCHAR2s_Table )
RETURN VARCHAR2s_Table
PARALLEL_ENABLE AGGREGATE USING Varchar2sTableUnion;
/
Abfrage :
Dann können Sie es einfach verwenden, um die Aggregation in Ihrer Abfrage durchzuführen:
WITH test_data (id, a_list) AS
(SELECT 1,
varchar2s_table ('A', 'B', 'C')
FROM DUAL
UNION ALL
SELECT 1,
varchar2s_table ('C', 'D', 'E')
FROM DUAL)
SELECT id,
MULTISET_UNION( a_list )
FROM test_data
GROUP BY id
Ausgabe :
ID MULTISET_UNION(A_LIST)
-- -------------------------------------------
1 SCHEMA.VARCHAR2S_TABLE('A','B','C','D','E')
