Oracle開發專題之：實現split 函數

功能描述：用指定分隔字元切割輸入的字串，返回一維數組，每個數組元素為一個子串。

原始碼：

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;
/
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;
/

測試：

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;
/
　

結果：
1
12
123
1234
12345