mysql加密函数与系统函数

### user() 查询用户
mysql> select user() from dual;
+----------------+
| user()         |
+----------------+
| root@localhost |
+----------------+

### database() 数据库名称
mysql> select database() from dual;
+------------+
| database() |
+------------+
| db03       |
+------------+

### md5(str)  为字符串算出一个MD5 32位的字符串
mysql> select md5("123456") from dual;
+----------------------------------+
| md5("123456")                    |
+----------------------------------+
| e10adc3949ba59abbe56e057f20f883e |
+----------------------------------+

### password(str)  通常用于mysql数据库加密
mysql> select password("123456") from dual;
+-------------------------------------------+
| password("123456")                        |
+-------------------------------------------+
| *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 |
+-------------------------------------------+

mysql> select authentication_string from mysql.user where user='root';
+-------------------------------------------+
| authentication_string                     |
+-------------------------------------------+
| *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 |
+-------------------------------------------+