利用mysql的inet_aton()和inet_ntoa()函数存储IP地址

mysql> create table jackbillow (ip int unsigned, name char(1));
Query OK, 0 rows affected (0.02 sec)



mysql> insert into jackbillow values(inet_aton('192.168.1.200'), 'A'), (inet_aton('200.100.30.241'), 'B');
Query OK, 2 rows affected (0.00 sec)
Records: 2 Duplicates: 0 Warnings: 0



mysql> insert into jackbillow values(inet_aton('24.89.35.27'), 'C'), (inet_aton('100.200.30.22'), 'D');
Query OK, 2 rows affected (0.00 sec)
Records: 2 Duplicates: 0 Warnings: 0

mysql> select * from jackbillow;
+------------+------+
| ip | name |
+------------+------+
| 3232235976 | A |
| 3362004721 | B |
| 408494875 | C |
| 1690836502 | D |
+------------+------+
4 rows in set (0.00 sec)



mysql> select * from jackbillow where ip = inet_aton('192.168.1.200');
+------------+------+
| ip | name |
+------------+------+
| 3232235976 | A |
+------------+------+
1 row in set (0.00 sec)



mysql> select inet_ntoa(ip) from jackbillow;
+----------------+
| inet_ntoa(ip) |
+----------------+
| 192.168.1.200 |
| 200.100.30.241 |
| 24.89.35.27 |
| 100.200.30.22 |
+----------------+
4 rows in set (0.00 sec)



当前很多应用都适用字符串char(15)来存储IP地址（占用16个字节），利用inet_aton()和inet_ntoa()函数，来存储IP地址效率很高，适用unsigned int 就可以满足需求，不需要使用bigint，只需要4个字节，节省存储空间，同时效率也高很多。

如果IP列有索引，可以使用下面方式查询：

mysql> select inet_aton('100.200.30.22');
+----------------------------+
| inet_aton('100.200.30.22') |
+----------------------------+
| 1690836502 |
+----------------------------+
1 row in set (0.00 sec)



mysql> select * from jackbillow where ip=1690836502;
+------------+------+
| ip | name |
+------------+------+
| 1690836502 | D |
+------------+------+
1 row in set (0.00 sec)

mysql> select inet_ntoa(ip),name from jackbillow where ip=1690836502;
+---------------+------+
| inet_ntoa(ip) | name |
+---------------+------+
| 100.200.30.22 | D |
+---------------+------+
1 row in set (0.00 sec)



对于LIKE操作，可以使用下面方式：

mysql> select inet_ntoa(ip) from jackbillow;
+----------------+
| inet_ntoa(ip) |
+----------------+
| 192.168.1.200 |
| 200.100.30.241 |
| 24.89.35.27 |
| 100.200.30.22 |
| 192.168.1.100 |
| 192.168.1.20 |
| 192.168.2.20 |
+----------------+
7 rows in set (0.00 sec)



mysql> select inet_aton('192.168.1.0');
+--------------------------+
| inet_aton('192.168.1.0') |
+--------------------------+
| 3232235776 |
+--------------------------+
1 row in set (0.00 sec)

mysql> select inet_aton('192.168.1.255');
+----------------------------+
| inet_aton('192.168.1.255') |
+----------------------------+
| 3232236031 |
+----------------------------+
1 row in set (0.00 sec)



mysql> select inet_ntoa(ip) from jackbillow where ip between 3232235776 and 3232236031;
+---------------+
| inet_ntoa(ip) |
+---------------+
| 192.168.1.200 |
| 192.168.1.100 |
| 192.168.1.20 |
+---------------+
3 rows in set (0.00 sec)



mysql> select inet_ntoa(ip) from jackbillow where ip between inet_aton('192.168.1.0') and inet_aton('192.168.1.255');
+---------------+
| inet_ntoa(ip) |
+---------------+
| 192.168.1.200 |
| 192.168.1.100 |
| 192.168.1.20 |
+---------------+
3 rows in set (0.00 sec)

整型字段的比较比字符串效率高很多，这也符合一项优化原则：字段类型定义使用最合适（最小），最简单的数据类型。

inet_aton()算法，其实借用了国际上对各国IP地址的区分中使用的ip number。

a.b.c.d 的ip number是：

a * 256的3次方 + b * 256的2次方 + c * 256的1次方 + d * 256的0次方。