Oracle字符串行专列(字符串聚合技术)(四)

2015-01-22 21:09:46 · 作者: · 浏览: 14
g VARCHAR2(32767);
BEGIN
  FOR i IN p_varchar2_tab.FIRST .. p_varchar2_tab.LAST LOOP
    IF i != p_varchar2_tab.FIRST THEN
      l_string := l_string || p_delimiter;
    END IF;
    l_string := l_string || p_varchar2_tab(i);
  END LOOP;
  RETURN l_string;
END tab_to_string;
/

The query below shows the COLLECT functionin action.

COLUMN employees FORMAT A50
 
SELECT deptno,
       tab_to_string(CAST(COLLECT(ename) AS t_varchar2_tab)) AS employees
FROM   emp
GROUP BY deptno;
       
    DEPTNO EMPLOYEES
---------- --------------------------------------------------
        10 CLARK,KING,MILLER
        20 SMITH,JONES,SCOTT,ADAMS,FORD
        30 ALLEN,WARD,MARTIN,BLAKE,TURNER,JAMES
        
3 rows selected.

?

-----------------------------------

Dylan Present.