Søg efter en værdi i kolonneværdien, der gemmer kommaseparerede værdier

Oracle-opsætning :

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;

Forespørgsel

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;

Output :

ACT_DATE  WEEKEND_FLAG
--------- ------------
06-FEB-16            1 
02-FEB-16            0 

Alternativ forespørgsel :

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;

Dette vil give det samme output og vil fungere for navne på dage, men vil ikke fungere for en generel sag, da du kan få et falsk positivt match til en understreng.