Oracle自定义一个把 IP 地址转成整数的函数

CREATE OR REPLACE FUNCTION fn_ipaddr_to_num (p_ipaddr VARCHAR2)
RETURN NUMBER
IS
v_ret NUMBER := 0;
k INT := 3;
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_ipaddr);

IF p_ipaddr IS NULL OR len = 0
THEN
RETURN 0;
ELSE
WHILE j < len
LOOP
j := INSTR (p_ipaddr, '.', i);

IF j = 0
THEN
j := len;
str := SUBSTR (p_ipaddr, i);
v_ret := v_ret + (TO_NUMBER (str) * POWER (256, k));

IF i >= len
THEN
EXIT;
END IF;
ELSE
str := SUBSTR (p_ipaddr, i, j - i);
i := j + 1;
v_ret := v_ret + (TO_NUMBER (str) * POWER (256, k));
END IF;

k := k - 1;
END LOOP;
END IF;

RETURN v_ret;
EXCEPTION
WHEN OTHERS
THEN
RAISE;
END fn_ipaddr_to_num;
/