本函數可以將“目標字符串”以“指定字符串”進行拆分,並通過表結構返回結果。代碼如下:
CREATE OR REPLACE TYPE str_split IS TABLE OF VARCHAR2 (4000);
CREATE OR REPLACE FUNCTION splitstr(p_string IN VARCHAR2, p_delimiter IN VARCHAR2)
RETURN str_split
PIPELINED
AS
v_length NUMBER := LENGTH(p_string);
v_start NUMBER := 1;
v_index NUMBER;
BEGIN
WHILE(v_start <= v_length)
LOOP
v_index := INSTR(p_string, p_delimiter, v_start);
IF v_index = 0
THEN
PIPE ROW(SUBSTR(p_string, v_start));
v_start := v_length + 1;
ELSE
PIPE ROW(SUBSTR(p_string, v_start, v_index - v_start));
v_start := v_index + 1;
END IF;
END LOOP;
RETURN;
END splitstr;
創建完畢後,我們來測試一下,例如執行如下SQL:
select * from table(splitstr('Hello,Cnblogs!',','));
其輸出結果爲一個兩行的表
將行轉爲列顯示:
select a.column_value v1,b.column_value v2 from
(select * from (select rownum rn,t.* from table(splitstr('Hello,Cnblogs!',',')) t)) a,
(select * from (select rownum rn,t.* from table(splitstr('Hello,Cnblogs!',',')) t)) b
where a.rn=1 and b.rn=2