在Oracle sql中将IPv4地址拆分为4个数字

Question

我正在尝试将给定的IPv4地址拆分为四个数字.

在SQL Server中,此查询适用于我:

select CAST (PARSENAME('10.20.30.40',4) AS INT) 

结果: 10

select CAST (PARSENAME('10.20.30.40',3) AS INT)

结果: 20

等等.

我需要Oracle SQL中的等效语法,但找不到它.任何的想法？

Answer 1

你可以使用regexp_substr:

select ip,
       regexp_substr(ip, '\d+',1,1) as first_octet,
       regexp_substr(ip, '\d+',1,2) as second_octet,
       regexp_substr(ip, '\d+',1,3) as third_octet,
       regexp_substr(ip, '\d+',1,4) as fourth_octet
from  (select '10.20.30.40' AS ip from dual )ips;

Rextester演示

Answer 2

您可以使用比正则表达式快得多的简单字符串函数（INSTR和SUBSTR）：

SQL小提琴

Oracle 11g R2架构设置：

CREATE TABLE sample_data ( ip_address ) AS
SELECT '10.20.30.40' FROM DUAL

查询1：

SELECT TO_NUMBER(
         SUBSTR( ip_address, 1, first_sep - 1 )
       ) AS ClassA,
       TO_NUMBER(
         SUBSTR( ip_address, first_sep + 1, second_sep - first_sep )
       ) AS ClassB,
       TO_NUMBER(
         SUBSTR( ip_address, second_sep + 1, third_sep - second_sep )
       ) AS ClassC,
       TO_NUMBER(
         SUBSTR( ip_address, third_sep + 1 )
       ) AS ClassD
FROM   (
  SELECT ip_address,
         INSTR( ip_address, '.', 1, 1 ) AS first_sep,
         INSTR( ip_address, '.', 1, 2 ) AS second_sep,
         INSTR( ip_address, '.', 1, 3 ) AS third_sep
  FROM   sample_data
)

结果：

| CLASSA | CLASSB | CLASSC | CLASSD |
|--------|--------|--------|--------|
|     10 |     20 |     30 |     40 |