oracle 比较字符串包含关系

CREATE OR REPLACE FUNCTION strContent(str1 IN VARCHAR2, str2 IN VARCHAR2)
  RETURN NUMBER IS
  Result     NUMBER;
  sStr       VARCHAR2(255);
  scharacter VARCHAR2(255);
  iIndex     NUMBER;
  sTemp      VARCHAR2(255);
BEGIN
  Result     := 0;
  scharacter := str1;
  sStr       := str2;
  iIndex     := INSTR(sStr, ',', 1);
  WHILE (iIndex > 0) LOOP
    iIndex := INSTR(sStr, ',', 1);
    IF (iIndex > 0) THEN
      sTemp := SUBSTR(sStr, 0, iIndex - 1);
    ELSE
      sTemp := sStr;//sTemp是str2拆分后的某一个字符串
    END IF;
    Result := INSTR(scharacter, sTemp, 1);//检查str1中出现sTemp的位置
    IF Result > 0 THEN
      RETURN Result;
    END IF;
        sStr := SUBSTR(sStr, iIndex + 1, LENGTH(sStr));
  END LOOP;
  RETURN Result;
END strContent;