（一）mysql基础和安装mysql5.7

（1）数据库系统

RDS：关系型，oracle，mysql，mariaDB，percona server ，DB2
NoSQL：Redis，MongoDB，memcache

（2）SQL语言：结构化查询语言

	DDL语句 数据定义语言：数据库丶表丶视图丶索引丶存储过程丶函数丶create drop alter
	DML语句	数据库操作语言：插入数据insert，删除数据delete丶更新数据update丶
	DQL语句	数据库查询语句：查询数据selete
	DCL语句	数据库控制语言：grant，revoke

（3）数据库访问技术

ODBC：php
JDBC：JAVA

（4）mysql安装方式

	二进制rpm：yum repository    mysql57-community-release-el7-9.noarch.rpm
	二进制预编译：	Generic mysql-5.7.16-linux-glibc2.5-x86_64.tar.gz
	源码编译安装：	source code   mysql-5.7.16.tar.gz

（5）yum安装mysql5.7

• 关闭防火墙和关闭selinux

systemctl stop firewalld
systemctl  disable firewalld

• 安装mysql官方yum源和安装mysql-server

rpm -ivh https://repo.mysql.com//mysql57-community-release-el7-11.noarch.rpm
yum makecache
yum repolist
yum install mysql-community-server -y

• 启动mysql

systemctl enable mysqld   
systemctl start mysqld	#mysql启动会进行数据库的初始化

• 数据目录和修改默认密码

yum安装的数据目录在/var/lib/mysql 
ll /var/lib/mysql  

• mysql 5.7之后默认root密码不为空，yum安装方式的随机密码生成在/var/log/mysqld.log，根据这个随机密码重置root密码

grep "password" /var/log/mysqld.log
2018-04-17T14:57:38.763497Z 1 [Note] A temporary password is generated for root@localhost: 1l79szme<=EJ

修改默认密码：mysqladmin -uroot -p'1l79szme<=EJ' password "Mysql@123"

（6）二进制方式安装mysql5.7.21

• 下载mysql5.7.21

mkdir /tools  &>/dev/null ; cd /tools
wget https://cdn.mysql.com//Downloads/MySQL-5.7/mysql-5.7.21-linux-glibc2.12-x86_64.tar.gz

• 创建用户和组

groupadd mysql
useradd -r -g mysql -s /bin/false mysql 

• 解压和创建软连接

tar xvf mysql-5.7.21-linux-glibc2.12-x86_64.tar.gz -C /usr/local
ln -sv /usr/local/mysql-5.7.21-linux-glibc2.12-x86_64 /usr/local/mysql 
chown -R mysql:mysql /usr/local/mysql 

• 创建mysql的数据目录和赋予权限

mkdir -pv /data/mydata
chown -R mysql:mysql /data/mydata

• mysql初始化

cd /usr/local/mysql
bin/mysqld --initialize --user=mysql --basedir=/usr/local/mysql --datadir=/data/mydata
	#会生成一个临时root密码：A temporary password is generated for root@localhost: pet3luts*F#R

• 创建mysql配置文件/etc/my.cnf

cp -rf /etc/my.cnf{,.old}
>/etc/my.cnf
[mysqld]
basedir=/usr/local/mysql
datadir=/data/mydata

• mysql启动脚本

cp support-files/mysql.server /etc/init.d/mysqld
chmod +x /etc/init.d/mysqld 
chkconfig --add /etc/init.d/mysqld
chkconfig mysqld on
echo "export PATH=/usr/local/mysql/bin:$PATH" >>/etc/profile
source /etc/profile

• 启动mysql

systemctl start mysqld
ss -anltup | grep 3306
ps -ef | grep mysqld

• 进入到mysql，需要重置mysql密码

mysql -uroot -p'pet3luts*F#R'
mysql> alter user root@'localhost' identified by 'MysqlMysql@123';
mysql> flush privileges;
或者使用这种方式修改：mysqladmin -uroot -p'MysqlMysql@123' password "Mysql@123"