oracle 实现 split 函数 (返回数组）

功能描述：用指定分隔符切割输入的字符串，返回一维数组，每个数组元素为一个子串。

源代码：

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;
/

测试：

DECLARE
  CURSOR c
  IS
    SELECT *
      FROM TABLE (CAST (fn_split ('1;;12;;123;;1234;;12345', ';;') AS ty_str_split
                  )
              );

  r c%ROWTYPE;
BEGIN
  OPEN c;

  LOOP
    FETCH c INTO r;

    EXIT WHEN c%NOTFOUND;
    DBMS_OUTPUT.put_line (r.column_value);
  END LOOP;

  CLOSE c;
END;
/
　
结果：
1
12
123
1234
12345