mysql> select curdate(),curtime(),now();
+------------+-----------+---------------------+
| curdate()  | curtime() | now()               |
+------------+-----------+---------------------+
| 2015-07-16 | 11:52:59  | 2015-07-16 11:52:59 |
+------------+-----------+---------------------+
1 row in set (0.00 sec)

mysql> select UNIX_TIMESTAMP(NOW());
+-----------------------+
| UNIX_TIMESTAMP(NOW()) |
+-----------------------+
|            1437015416 |
+-----------------------+
1 row in set (0.00 sec)

mysql> SELECT FROM_UNIXTIME(1437015416);
+---------------------------+
| FROM_UNIXTIME(1437015416) |
+---------------------------+
| 2015-07-16 11:56:56       |
+---------------------------+
1 row in set (0.00 sec)

mysql> SELECT WEEK(NOW()),YEAR(NOW());
+-------------+-------------+
| WEEK(NOW()) | YEAR(NOW()) |
+-------------+-------------+
|          28 |        2015 |
+-------------+-------------+
1 row in set (0.00 sec)

mysql> SELECT HOUR(CURTIME()),MINUTE(CURTIME());
+-----------------+-------------------+
| HOUR(CURTIME()) | MINUTE(CURTIME()) |
+-----------------+-------------------+
|              12 |                 0 |
+-----------------+-------------------+
1 row in set (0.00 sec)

mysql> SELECT MONTHNAME(NOW());
+------------------+
| MONTHNAME(NOW()) |
+------------------+
| July             |
+------------------+
1 row in set (0.00 sec)

mysql> SELECT DATE_FORMAT(now(),'%M','%D','%Y');
ERROR 1582 (42000): Incorrect parameter count in the call to native function 'DATE_FORMAT'
mysql> SELECT DATE_FORMAT(now(),'%M,%D,%Y');
+-------------------------------+
| DATE_FORMAT(now(),'%M,%D,%Y') |
+-------------------------------+
| July,16th,2015                |
+-------------------------------+
1 row in set (0.00 sec)

mysql> SELECT MONTHNAME(NOW());
+------------------+
| MONTHNAME(NOW()) |
+------------------+
| July             |
+------------------+
1 row in set (0.00 sec)

mysql> SELECT DATE_FORMAT(now(),'%M','%D','%Y');
ERROR 1582 (42000): Incorrect parameter count in the call to native function 'DATE_FORMAT'
mysql> SELECT DATE_FORMAT(now(),'%M,%D,%Y');
+-------------------------------+
| DATE_FORMAT(now(),'%M,%D,%Y') |
+-------------------------------+
| July,16th,2015                |
+-------------------------------+
1 row in set (0.00 sec)

mysql> set lc_time_names='zh_CN';
Query OK, 0 rows affected (0.00 sec)

mysql> SELECT DATE_FORMAT(now(),'%M,%D,%Y');
+-------------------------------+
| DATE_FORMAT(now(),'%M,%D,%Y') |
+-------------------------------+
| 七月,16th,2015                |
+-------------------------------+
1 row in set (0.00 sec)

+------------+-----------+----------------+
| database() | version() | user()         |
+------------+-----------+----------------+
| test       | 5.6.23    | root@localhost |
+------------+-----------+----------------+
1 row in set (0.00 sec)

mysql> select inet_aton('192.169.1.1');
+--------------------------+
| inet_aton('192.169.1.1') |
+--------------------------+
|               3232301313 |
+--------------------------+
1 row in set (0.00 sec)

mysql> select inet_ntoa('3232301313');
+-------------------------+
| inet_ntoa('3232301313') |
+-------------------------+
| 192.169.1.1             |
+-------------------------+
1 row in set (0.00 sec)

mysql> drop table t;
Query OK, 0 rows affected (0.05 sec)

mysql> create table t(id varchar(20));
Query OK, 0 rows affected (0.99 sec)

mysql> insert into t values('192.168.1.1');
Query OK, 1 row affected (0.01 sec)

mysql> insert into t values('192.168.1.3');
Query OK, 1 row affected (0.01 sec)

mysql> insert into t values('192.168.1.6');
Query OK, 1 row affected (0.00 sec)

mysql> insert into t values('192.168.1.10');
Query OK, 1 row affected (0.00 sec)

mysql> insert into t values('192.168.1.20');
Query OK, 1 row affected (0.01 sec)

mysql> insert into t values('192.168.1.30');
Query OK, 1 row affected (0.01 sec)

mysql> commit;
Query OK, 0 rows affected (0.00 sec)

mysql> select * from t;
+--------------+
| id           |
+--------------+
| 192.168.1.1  |
| 192.168.1.3  |
| 192.168.1.6  |
| 192.168.1.10 |
| 192.168.1.20 |
| 192.168.1.30 |
+--------------+
6 rows in set (0.00 sec)

mysql> select * from t where id>='192.168.1.3' and id <='192.168.1.20';
Empty set (0.00 sec)

mysql> select * from t where inet_aton(id)>=inet_aton('192.168.1.3') and inet_aton(id) <=inet_aton('192.168.1.20');
+--------------+
| id           |
+--------------+
| 192.168.1.3  |
| 192.168.1.6  |
| 192.168.1.10 |
| 192.168.1.20 |
+--------------+
4 rows in set (0.00 sec)

mysql> select password('123456');
+-------------------------------------------+
| password('123456')                        |
+-------------------------------------------+
| *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 |
+-------------------------------------------+
1 row in set (0.00 sec)

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