oracle数据库split()函数的实现代码

CREATE OR REPLACE TYPE ty_str_split IS TABLE OF VARCHAR2 (4000) 
CREATE OR REPLACE FUNCTION fn_split (p_str IN VARCHAR2, p_delimiter IN VARCHAR2) 
    RETURN ty_str_split 
IS 
    j INT := 0; 
    i INT := 1; 
    len INT := 0; 
    len1 INT := 0; 
    str VARCHAR2 (4000); 
    str_split ty_str_split := ty_str_split (); 
BEGIN 
    len := LENGTH (p_str); 
    len1 := LENGTH (p_delimiter); 
 
    WHILE j < len 
    LOOP 
        j := INSTR (p_str, p_delimiter, i); 
 
        IF j = 0 
        THEN 
            j := len; 
            str := SUBSTR (p_str, i); 
            str_split.EXTEND; 
            str_split (str_split.COUNT) := str; 
 
            IF i >= len 
            THEN 
                EXIT; 
            END IF; 
        ELSE 
            str := SUBSTR (p_str, i, j - i); 
            i := j + len1; 
            str_split.EXTEND; 
            str_split (str_split.COUNT) := str; 
        END IF; 
    END LOOP; 
 
    RETURN str_split; 
END fn_split; 

select fn_split('1,2,3,4,',',') from dual; 
select t.* from (SELECT *   FROM TABLE (CAST (fn_split ('1;;12;;123;;1234;;12345', ';;') AS ty_str_split)))t