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。有什么想法吗？

Answer 1

您可以使用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;

<强> Rextester Demo

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 Fiddle

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
)

<强> Results ：

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

Answer 3

如果您需要一个功能，这是另一个解决方案：

SELECT REGEXP_SUBSTR('10.20.30.40', '\d+', 1, LEVEL) as octet, level
FROM dual 
CONNECT BY LEVEL <= 4;


OCTET   LEVEL
10      1
20      2
30      3
40      4

在Oracle sql中将IPv4地址拆分为4个数字

3 个答案: