[root@b ~]# mysql -uroot -pxxxxxxxx　　　　　　　　　　#mysql登陆方式
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 6
Server version: 5.7.20 Source distribution

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Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql>

mysql> show databases;　　　　　　　　　　　　　　#查看所有的数据库
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| sys |
+--------------------+
5 rows in set (0.00 sec)

mysql> use mysql;　　　　　　　　　　　　　　　　#进入mysql数据库；
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed

mysql> show tables;　　　　　　　　　　　　#查看数据库里有多少张表
+---------------------------+
| Tables_in_mysql |
+---------------------------+
| columns_priv |
| db |
| engine_cost |
| event |
| func |
| general_log |
| help_topic |
| innodb_table_stats |
| ndb_binlog_index |
| plugin |
| user |
+---------------------------+
11 rows in set (0.00 sec)

mysql> create database lisi;　　　　　　　　#创建名为lisi的数据库
Query OK, 1 row affected (0.06 sec)

mysql> create table t1 (id varchar(20),name varchar(20));　　　　#创建名为t1表，并创建两个字
Query OK, 0 rows affected (0.08 sec)

mysql> insert into t1 values("1","hello");　　　　　　　　　　#向表中插入数据
Query OK, 1 row affected (0.01 sec)

mysql> select * from t1;　　　　　　　　　　　　　　#查看t1表数据内容
+------+-------+
| id | name |
+------+-------+
| 1 | hello |
+------+-------+
1 row in set (0.00 sec)

mysql> select * from t1 where id=1 and name='hello';　　　　#id、name多个条件查询
+------+-------+
| id | name |
+------+-------+
| 1 | hello |
+------+-------+
1 row in set (0.00 sec)

mysql> desc t1;　　　　　　　　　　　　　　　　　　#查看t1表字段内容
+-------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+-------------+------+-----+---------+-------+
| id | varchar(20) | YES | | NULL | |
| name | varchar(20) | YES | | NULL | |
+-------+-------------+------+-----+---------+-------+
2 rows in set (0.01 sec)

mysql> flush privileges;　　　　　　　　　　　　　　#刷新权限
Query OK, 0 rows affected (0.00 sec)

mysql> delete from t1;　　　　　　　　　　　　　　#清空表内容
Query OK, 1 row affected (0.09 sec)

mysql> desc t1;
+-------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+-------------+------+-----+---------+-------+
| id | varchar(20) | YES | | NULL | |
| name | varchar(20) | YES | | NULL | |
+-------+-------------+------+-----+---------+-------+
2 rows in set (0.00 sec)

mysql> select * from t1;
Empty set (0.00 sec)

mysql> drop table t1;　　　　　　　　　　　　#删除表
Query OK, 0 rows affected (0.06 sec)

mysql> show tables;
Empty set (0.00 sec)

mysql> drop database mysql;　　　　　　　　#删除mysql数据库

Query OK, 0 rows affected (0.00 sec)

mysql> exit　　　　　　　　　　　　　　　　#退出数据库
Bye

[root@b ~]#mysqldump -uroot -pxxxxxxxx  lisi> lisi.sql　　　　　　　　#备份lisi数据库为lisi.sql