To løsninger, der kun bruger SQL og en tredje løsning, der bruger en lille/simpel PL/SQL-funktion, som giver en meget kort endelig SQL-forespørgsel.
Oracle-opsætning :
CREATE TABLE data ( value ) AS
SELECT 'POW,POW,POWPRO,PRO,PRO,PROUTL,TNEUTL,TNEUTL,UTL,UTLTNE,UTL,UTLTNE' FROM DUAL;
CREATE TYPE stringlist AS TABLE OF VARCHAR2(4000);
/
Forespørgsel 1 :
SELECT LISTAGG( t.COLUMN_VALUE, ',' ) WITHIN GROUP ( ORDER BY t.COLUMN_VALUE ) AS list
FROM data d,
TABLE(
SET(
CAST(
MULTISET(
SELECT REGEXP_SUBSTR( d.value, '[^,]+', 1, LEVEL )
FROM DUAL
CONNECT BY LEVEL <= REGEXP_COUNT( d.value, '[^,]+' )
) AS stringlist
)
)
) t
GROUP BY d.value;
Udgange :
LIST
---------------------------------------
POW,POWPRO,PRO,PROUTL,TNEUTL,UTL,UTLTNE
Forespørgsel 2 :
SELECT ( SELECT LISTAGG( COLUMN_VALUE, ',' ) WITHIN GROUP ( ORDER BY ROWNUM )
FROM TABLE( d.uniques ) ) AS list
FROM (
SELECT ( SELECT CAST(
COLLECT(
DISTINCT
REGEXP_SUBSTR( d.value, '[^,]+', 1, LEVEL )
)
AS stringlist
)
FROM DUAL
CONNECT BY LEVEL <= REGEXP_COUNT( d.value, '[^,]+' )
) uniques
FROM data d
) d;
Output :
LIST
---------------------------------------
POW,POWPRO,PRO,PROUTL,TNEUTL,UTL,UTLTNE
Oracle-opsætning :
En lille hjælpefunktion:
CREATE FUNCTION split_String(
i_str IN VARCHAR2,
i_delim IN VARCHAR2 DEFAULT ','
) RETURN stringlist DETERMINISTIC
AS
p_result stringlist := stringlist();
p_start NUMBER(5) := 1;
p_end NUMBER(5);
c_len CONSTANT NUMBER(5) := LENGTH( i_str );
c_ld CONSTANT NUMBER(5) := LENGTH( i_delim );
BEGIN
IF c_len > 0 THEN
p_end := INSTR( i_str, i_delim, p_start );
WHILE p_end > 0 LOOP
p_result.EXTEND;
p_result( p_result.COUNT ) := SUBSTR( i_str, p_start, p_end - p_start );
p_start := p_end + c_ld;
p_end := INSTR( i_str, i_delim, p_start );
END LOOP;
IF p_start <= c_len + 1 THEN
p_result.EXTEND;
p_result( p_result.COUNT ) := SUBSTR( i_str, p_start, c_len - p_start + 1 );
END IF;
END IF;
RETURN p_result;
END;
/
Forespørgsel 3 :
SELECT ( SELECT LISTAGG( COLUMN_VALUE, ',' ) WITHIN GROUP ( ORDER BY ROWNUM )
FROM TABLE( SET( split_String( d.value ) ) ) ) AS list
FROM data d;
eller (hvis du kun vil videregive en enkelt værdi):
SELECT LISTAGG( COLUMN_VALUE, ',' ) WITHIN GROUP ( ORDER BY ROWNUM ) AS list
FROM TABLE( SET( split_String(
'POW,POW,POWPRO,PRO,PRO,PROUTL,TNEUTL,TNEUTL,UTL,UTLTNE,UTL,UTLTNE'
) ) );
Output :
LIST
---------------------------------------
POW,POWPRO,PRO,PROUTL,TNEUTL,UTL,UTLTNE