安装mysql
#这里是安装mysql的源
yum install -y https://repo.mysql.com//mysql80-community-release-el7-3.noarch.rpm
检查MySQL源是否安装成功
yum repolist enabled
部分结果：
mysql-connectors-community/x86_64 MySQL Connectors Community
mysql-tools-community/x86_64 MySQL Tools Community
mysql80-community/x86_64 MySQL 8.0 Community Server
源安装完以后 安装mysql服务
yum install mysql-community-server
Transaction test succeeded
Running transaction
Installing : mysql-community-common-8.0.21-1.el7.x86_64 1/7
Installing : mysql-community-libs-8.0.21-1.el7.x86_64 2/7
Installing : mysql-community-client-8.0.21-1.el7.x86_64 3/7
Installing : net-tools-2.0-0.25.20131004git.el7.x86_64 4/7
Installing : mysql-community-server-8.0.21-1.el7.x86_64 5/7
Installing : mysql-community-libs-compat-8.0.21-1.el7.x86_64 6/7
Erasing : 1:mariadb-libs-5.5.65-1.el7.x86_64 7/7
Verifying : mysql-community-server-8.0.21-1.el7.x86_64 1/7
Verifying : mysql-community-libs-8.0.21-1.el7.x86_64 2/7
Verifying : mysql-community-client-8.0.21-1.el7.x86_64 3/7
Verifying : mysql-community-libs-compat-8.0.21-1.el7.x86_64 4/7
Verifying : net-tools-2.0-0.25.20131004git.el7.x86_64 5/7
Verifying : mysql-community-common-8.0.21-1.el7.x86_64 6/7
Verifying : 1:mariadb-libs-5.5.65-1.el7.x86_64 7/7
Installed:
mysql-community-libs.x86_64 0:8.0.21-1.el7 mysql-community-libs-compat.x86_64 0:8.0.21-1.el7
mysql-community-server.x86_64 0:8.0.21-1.el7
Dependency Installed:
mysql-community-client.x86_64 0:8.0.21-1.el7 mysql-community-common.x86_64 0:8.0.21-1.el7
net-tools.x86_64 0:2.0-0.25.20131004git.el7
Replaced:
mariadb-libs.x86_64 1:5.5.65-1.el7
需要安装
Total download size: 553 M
mysql服务操作
# 启动服务
systemctl start mysqld
# 查看服务
systemctl status mysqld
mysqld.service - MySQL Server
Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled; vendor preset: disabled)
Active: active (running) since Sat 2020-08-01 16:06:52 EDT; 12s ago
修改mysql中root本地密码
先在日志中查找 生成的密码
grep 'temporary password' /var/log/mysqld.log
[root@bogon ~]# grep 'temporary password' /var/log/mysqld.log
2020-08-01T20:06:49.105603Z 6 [Note] [MY-010454] [Server] A temporary password is generated for root@localhost: J<wGLsguq9?n
使用密码root登录
mysql -u root -p
不过进行其他操作的时候，会发现 提示你用alert 语句去修改密码，这个密码只是临时密码。
mysql> use mysql
ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.
修改密码
# ALTER USER 'root'@'localhost' IDENTIFIED BY '密码';
密码组成：
xxxxxxxxxx mysql> show global variables like '%validate_password%';+--------------------------------------+--------+| Variable_name | Value |+--------------------------------------+--------+| validate_password.check_user_name | ON || validate_password.dictionary_file | || validate_password.length | 8 || validate_password.mixed_case_count | 1 || validate_password.number_count | 1 || validate_password.policy | MEDIUM || validate_password.special_char_count | 1 |+--------------------------------------+--------+# 解释validate_password_dictionary_file ：验证密码的字典文件,与之相同的不可使用validate_password_length ：密码最少长度validate_password_number_count ：最少数字字符数validate_password_mixed_case_count ：最少大写和小写字符数(同时有大写和小写)validate_password_special_char_count ：最少特殊字符数validate_password_policy ：密码安全策略 LOW: 只限制长度 MEDIUM： 限制长度、数字、字母、特殊字符 STRONG： 限制长度、数字、字母、特殊字符、字典#默认是中等，密码必须由 大写字母、小写字母、数字、特殊字符组成 且长度为8位
在/etc/my.cnf文件添加validate_password_policy配置，指定密码策略
选择0（LOW），1（MEDIUM），2（STRONG）其中一种，选择2需要提供密码字典文件
validate_password_policy=0
如果不需要密码策略，添加my.cnf文件中添加如下配置禁用即可：
validate_password = off
重新启动mysql服务使配置生效：
systemctl restart mysqld
允许远程登录
MySQL默认只允许root帐户在本地登录，想要远程连接MySQL，必须开启root用户允许远程连接，或者添加一个允许远程连接的帐户。
首先查看mysql的 user表
select * from user \G
*************************** 4. row ***************************
Host: localhost
User: root
Select_priv: Y
Insert_priv: Y
Update_priv: Y
Delete_priv: Y
Create_priv: Y
Drop_priv: Y
Reload_priv: Y
Shutdown_priv: Y
Process_priv: Y
File_priv: Y
Grant_priv: Y
References_priv: Y
Index_priv: Y
Alter_priv: Y
Show_db_priv: Y
Super_priv: Y
Create_tmp_table_priv: Y
Lock_tables_priv: Y
Execute_priv: Y
Repl_slave_priv: Y
Repl_client_priv: Y
Create_view_priv: Y
Show_view_priv: Y
Create_routine_priv: Y
Alter_routine_priv: Y
Create_user_priv: Y
Event_priv: Y
Trigger_priv: Y
Create_tablespace_priv: Y
ssl_type:
ssl_cipher: 0x
x509_issuer: 0x
x509_subject: 0x
max_questions: 0
max_updates: 0
max_connections: 0
max_user_connections: 0
plugin: caching_sha2_password
authentication_string: $A$005$QVf`
hi@? _:w.FDDatpHPPpgl.7j830gDg9X.HbKF05PzcdmXptHuD
password_expired: N
password_last_changed: 2020-08-03 20:01:07
password_lifetime: NULL
account_locked: N
Create_role_priv: Y
Drop_role_priv: Y
Password_reuse_history: NULL
Password_reuse_time: NULL
Password_require_current: NULL
User_attributes: NULL
4 rows in set (0.01 sec)
可以看到 root用户默认只能访问localhost 也就是只能本地登录，不能远程登录。
查询mysql具体版本
SELECT @@VERSION
mysql> select @@VERSION;
+-----------+
| @@VERSION |
+-----------+
| 8.0.21 |
+-----------+
此版的的mysql版本把将创建账户和赋予权限分开了
早期可以合二为一
GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY '密码' WITH GRANT OPTION;
创建可以远程访问的root用户
create user 'root'@'%' identified by '密码';
给远程root用户赋予权限
grant all privileges on *.* to 'root'@'%' with grant option;
操作后要执行刷新，远程用户才能有效
flush privileges;
查看数据库使用的字符集
show variables like '%character%%'
MySQL忘记root用户密码，解决方案
在 /etc/my.cnf文件[mysqld]下面加如下命令
[mysqld]
skip-grant-tables #设置为跳过授权认证 不验证密码
mysql -u root
#update mysql.user set authentication_string=password('newPass') where user='root' and #Host = 'localhost';
flush privileges
ALTER USER 'root'@'localhost' IDENTIFIED BY '密码';
flush privileges