卸载内置环境 

查看是否存在MySQL

ps axj | grep mysql

关闭MySQL 

systemctl stop mysqld

 MySQL对应的安装文件

rpm -qa | grep mysql

批量卸载

rpm -qa | grep mysql | xargs yum -y remove

上传MySQL 

rz 

 查看本地yum源

ls /etc/yum.repos.d/ -a

 安装MySQL

 rpm -ivh mysql57-community-release-el7.rpm

查看Linux版本

cat /etc/redhat-release

显示数据库show databases

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
4 rows in set (0.02 sec)

/var/lib/mysql

 会多一个目录。

创建 

mysql> create database database1;

删除

mysql> drop database database1;

数据库的两个编码集

1.数据库编码集  数据库未来存储数据

2.数据库校验集  支持数据库，进行比较使用的编码，本质也是一种数据库中数据采用的编码方式。

数据库无论是对数据做任何操作，都必须保证操作和编码是一致的。

字符集和校验规则

查看系统默认字符集以及校验规则

show variables like 'character_set_database';
show variables like 'collation_database';

查看数据库支持的字符集

show charset;

查看数据库支持的字符集校验规则

show collation;

create database d1 charset=utf8 collate utf8_general_ci;

对其进行设置。

mysql> create database test1 collate utf8_general_ci;

mysql> create database test1 collate utf8_general_ci;
Query OK, 1 row affected, 1 warning (0.02 sec)

mysql> create database test2 collate utf8_bin;

mysql> create database test2 collate utf8_bin;
Query OK, 1 row affected, 1 warning (0.02 sec)

mysql> create table person(name varchar(20));

不区分大小写  utf8_general_ci

mysql> select * from person where name='a';
+------+
| name |
+------+
| a    |
| A    |
+------+

区分大小写  utf8_bin

mysql> use test2
Database changed
mysql> create table person(name varchar(20));
Query OK, 0 rows affected (0.06 sec)

mysql> insert into person (name) values ('a');
Query OK, 1 row affected (0.01 sec)

mysql> insert into person (name) values ('A');
Query OK, 1 row affected (0.02 sec)

mysql> select * from person where name='a';
+------+
| name |
+------+
| a    |
+------+

显示

mysql> show tables;
+-----------------+
| Tables_in_test1 |
+-----------------+
| person          |
+-----------------+
1 row in set (0.01 sec)

desc

mysql> desc person;
+-------+-------------+------+-----+---------+-------+
| Field | Type        | Null | Key | Default | Extra |
+-------+-------------+------+-----+---------+-------+
| name  | varchar(20) | YES  |     | NULL    |       |
+-------+-------------+------+-----+---------+-------+
1 row in set (0.01 sec)

select （DQL）

mysql> select * form person;

 插入

mysql> insert into person (name) values ('D');

order by

mysql> select * form person order by name;