Mysql的其他函数

database()

返回当前数据库名

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| db_springcloud     |
| mysql              |
| performance_schema |
| test               |
| wordpress          |
| xinyu              |
| xinyu2             |
| zabbix             |
+--------------------+
9 rows in set (0.00 sec)

mysql> use test;
Database changed
mysql> select database();
+------------+
| database() |
+------------+
| test       |
+------------+
1 row in set (0.00 sec)

version()

返回当前数据库版本

mysql> select version();
+-----------+
| version() |
+-----------+
| 5.6.33    |
+-----------+
1 row in set (0.00 sec)

user()

返回当前登录用户名

mysql> select user();
+----------------+
| user()         |
+----------------+
| root@localhost |
+----------------+
1 row in set (0.00 sec)

inet_aton(ip)

返回ip地址的数字表示

mysql> select inet_aton('192.168.8.133');
+----------------------------+
| inet_aton('192.168.8.133') |
+----------------------------+
|                 3232237701 |
+----------------------------+
1 row in set (0.00 sec)

inet_ntoa(ip)

跟inet_aton(ip)刚好相反，返回数字代表的ip地址

mysql> select inet_ntoa('3232237701');
+-------------------------+
| inet_ntoa('3232237701') |
+-------------------------+
| 192.168.8.133           |
+-------------------------+
1 row in set (0.00 sec)

password(str)

返回字符串str的加密版本，加密单向不可逆。适用于mysql数据库的用户密码加密

mysql> select password('123456');
+-------------------------------------------+
| password('123456')                        |
+-------------------------------------------+
| *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 |
+-------------------------------------------+
1 row in set (0.01 sec)

md5(str)

返回字符串str的MD5值，该值以32位十六进制的二进制字符串的形式返回

mysql> select md5('123456');
+----------------------------------+
| md5('123456')                    |
+----------------------------------+
| e10adc3949ba59abbe56e057f20f883e |
+----------------------------------+
1 row in set (0.00 sec)