Impostazione Oracle :
CREATE OR REPLACE FUNCTION split_String(
i_str IN VARCHAR2,
i_delim IN VARCHAR2 DEFAULT ','
) RETURN SYS.ODCIVARCHAR2LIST DETERMINISTIC
AS
p_result SYS.ODCIVARCHAR2LIST := SYS.ODCIVARCHAR2LIST();
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;
/
CREATE TABLE xyz ( weekend_days ) AS
SELECT 'SATURDAY,SUNDAY' FROM DUAL;
CREATE TABLE abc ( act_date ) AS
SELECT DATE '2016-02-02' FROM DUAL UNION ALL
SELECT DATE '2016-02-06' FROM DUAL;
Richiesta
SELECT act_date,
CASE WHEN w.Weekend_day IS NULL THEN 0 ELSE 1 END AS weekend_flag
FROM abc a
LEFT OUTER JOIN
( SELECT t.column_value AS weekend_day
FROM xyz x,
TABLE( split_String( x.weekend_days ) ) t
) w
ON TRIM( TO_CHAR( a.ACT_DATE, 'DAY' ) ) = w.Weekend_day;
Risultato :
ACT_DATE WEEKEND_FLAG
--------- ------------
06-FEB-16 1
02-FEB-16 0
Query alternativa :
SELECT act_date,
CASE
WHEN INSTR( x.weekend_days, TRIM( TO_CHAR( act_date, 'DAY' ) ) ) > 0
THEN 1
ELSE 0
END AS weekend_flag
FROM abc a
CROSS JOIN
xyz x;
Questo darà lo stesso output e funzionerà per i nomi dei giorni ma non funzionerà per un caso generale poiché potresti ottenere una corrispondenza falsa positiva per una sottostringa.
