常用的MySQL的指令

1、启动并登陆MySQL

C:\WINDOWS\system32>mysql -uroot -p
Enter password: ******
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 5
Server version: 5.5.44 MySQL Community Server (GPL)

2、修改操作符，查看版本

mysql> prompt \u@\h \d>
PROMPT set to '\u@\h \d>'
root@localhost (none)>use test;
Database changed
root@localhost test>select version();
+-----------+
| version() |
+-----------+
| 5.5.44    |
+-----------+
1 row in set (0.00 sec)

3、查看当前的时间和用户

root@localhost test>select now();
+---------------------+
| now()               |
+---------------------+
| 2017-07-16 10:27:53 |
+---------------------+
1 row in set (0.00 sec)

root@localhost test>select user();
+--------+
| user() |
+--------+
| root@  |
+--------+
1 row in set (0.00 sec)
4、创建数据库，查看所有数据库

root@localhost test>CREATE DATABASE t1;
Query OK, 1 row affected (0.00 sec)

root@localhost test>SHOW DATABASES;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| t1                 |
| test               |
+--------------------+
5 rows in set (0.00 sec)

5、重复创建数据库及警告查看

root@localhost test>CREATE DATABASE t1;
ERROR 1007 (HY000): Can't create database 't1'; database exists
root@localhost test>CREATE DATABASE IF NOT EXISTS t1;
Query OK, 1 row affected, 1 warning (0.00 sec)
root@localhost test>SHOW WARNINGS;
+-------+------+---------------------------------------------+
| Level | Code | Message                                     |
+-------+------+---------------------------------------------+
| Note  | 1007 | Can't create database 't1'; database exists |
+-------+------+---------------------------------------------+
1 row in set (0.00 sec)

6、查看数据库编码方式与修改编码方式

root@localhost test>SHOW CREATE DATABASE t2;
+----------+------------------------------------------------------------+
| Database | Create Database                                            |
+----------+------------------------------------------------------------+
| t2       | CREATE DATABASE `t2` /*!40100 DEFAULT CHARACTER SET gbk */ |
+----------+------------------------------------------------------------+
1 row in set (0.00 sec)

root@localhost test>ALTER DATABASE t2 CHARACTER SET = utf8;
Query OK, 1 row affected (0.00 sec)

7、查看数据库和删除数据库

root@localhost test>DROP DATABASE t1;
Query OK, 0 rows affected (0.01 sec)
root@localhost test>SHOW DATABASES;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| t2                 |
| test               |
+--------------------+
5 rows in set (0.00 sec)