安裝前註意：

MySQL8.0和MySQL5.7和之前的版本還是有區別的，第一點就是在安裝MySQL的時候 密碼認證方式：默認的密碼加密方式是：caching_sha2_password，而現在很多客戶端工具還不支持這種加密認證方式，可以在配置文件中加入：default_authentication_plugin=mysql_native_password；這樣就和MySQL5.7和之前的版本一樣了。

1、下載二進制軟件包：

mysql-8.0.11-linux-glibc2.12-x86_64.tar.gz

2、添加MySQL用戶和組：

[root@localhost ~]# userdel mysql   （因為是新系統，所以就把現有的MySQL用戶給刪除了）
   [root@localhost ~]# groupadd mysql
   [root@localhost ~]# useradd -g mysql  mysql
   [root@localhost ~]# passwd mysql      （MySQL密碼要設置的復雜一點，或者在創建用戶的時候設置不讓登陸系統）

3、創建安裝MySQL目標，並解壓軟件到指定目錄

 [root@localhost ~]# mkdir -p /mysql/data
   [root@localhost ~]# chown -R mysql.mysql /mysql
   [root@localhost ~]# tar zxvf  mysql-8.0.11-linux-glibc2.12-x86_64.tar.gz -C /mysql
   [root@localhost ~]# cd /mysql
   [root@localhost ~]# mv mysql-8.0.11-linux-glibc2.12-x86_64 / mysql
   [root@localhost ~]# chown -R mysql.mysql /mysql

4、初始化數據庫

[root@localhost ~]# su - mysql

[mysql@localhost ~]$ vim /mysql/my.cnf

[client]
socket=/mysql/data/mysql.sock
[mysqld]
server-id=142
port = 3306
basedir=/mysql/mysql
datadir=/mysql/data
socket=/mysql/data/mysql.sock
log-error=/mysql/data/mysqld.log
pid-file=/mysql/data/mysqld.pid
log-bin=/mysql/data/binlog
slow_query_log_file = /mysql/data/slow.log
log_slave_updates
expire_logs_days=7
binlog_format=ROW
#default_authentication_plugin=mysql_native_password    ---修改密碼加密方式。（看文中最後的解釋）
gtid-mode = on  
enforce-gtid-consistency = 1  
skip_slave_start=1  
innodb_buffer_pool_size   = 1000M                           
innodb_buffer_pool_instances = 2                          
innodb_log_file_size      = 100M                           
innodb_log_files_in_group = 3                             
innodb_log_buffer_size    = 24M                          
innodb_flush_log_at_trx_commit = 1                        
innodb_file_per_table     = 1                             
innodb_flush_method       = O_DIRECT                      
innodb_io_capacity        = 200                           
innodb_io_capacity_max    = 600                           
innodb_thread_concurrency = 0                             
innodb_autoinc_lock_mode  = 2                             
innodb_lock_wait_timeout  = 60                            
innodb_read_io_threads    = 4                 
innodb_write_io_threads   = 4                                  
innodb_max_dirty_pages_pct = 80                                
innodb_autoextend_increment = 512                              
innodb_checksum_algorithm = NONE   
max_connect_errors        = 1000                            
max_connections           = 500                                
connect_timeout           = 300                                
wait_timeout              = 86400                              
interactive_timeout       = 86400

[mysql@localhost mysql]$ /mysql/mysql/bin/mysqld --defaults-file=/mysql/my.cnf  --user=mysql --basedir=/mysql/mysql/ --datadir=/mysql/data/  --initialize

其中，root的默認密碼在：/mysql/data/mysqld.log 日誌中，打開查看即可

5、啟動MySQL

[root@localhost mysql]#  /mysql/mysql/bin/mysqld_safe --defaults-file=/mysql/my.cnf  --user=mysql &
[root@localhost mysql]# /mysql/mysql/bin/mysql -uroot -p -S /mysql/data/mysql.sock    
mysql> set password='123456';
mysql> flush privileges;
mysql> \s
--------------
/mysql/mysql/bin/mysql  Ver 8.0.11 for linux-glibc2.12 on x86_64 (MySQL Community Server - GPL)
Connection id:          11
Current database:
Current user:           root@localhost
SSL:                    Not in use
Current pager:          stdout
Using outfile:          ''
Using delimiter:        ;
Server version:         8.0.11 MySQL Community Server - GPL
Protocol version:       10
Connection:             Localhost via UNIX socket
Server characterset:    utf8mb4
Db     characterset:    utf8mb4
Client characterset:    utf8mb4
Conn.  characterset:    utf8mb4
UNIX socket:            /mysql/data/mysql.sock
Uptime:                 10 min 31 sec
Threads: 2  Questions: 10  Slow queries: 0  Opens: 124  Flush tables: 2  Open tables: 100  Queries per second avg: 0.015
--------------

（註意：這裏啟動數據庫一定要用MySQL8.0安裝包自帶的客戶端才可以登錄，即要使用MySQL8.0安裝包的命令進行登錄數據庫，要不然會報錯，如：

ERROR 2059 (HY000): Authentication plugin 'caching_sha2_password' cannot be loaded:）

註意：

在mysql8.0下,默認變成了default_authentication_plugin=caching_sha2_password,包括你剛初始化的root用戶也是這個認證加密方式,這樣的結果是讓你除非用新的協議驅動,例如必須用8.0自帶的mysql客戶端才行,不然就連接不上數據庫.

在mysql5.7環境裏,雖然可以設置default_authentication_plugin來改變認證加密方式,但是一般人不會去設置.所以默認使用的認證加密方式是mysql_native_password

解決方法：

①：在初始化的時候在配置文件中加入，如下，mysql_native_password 這種認證方法就會很多客戶端的認證加密方式一樣。

vim my.cnf

[mysqld]

default_authentication_plugin=mysql_native_password

②：使用命令行模式更改用戶的密碼加密認證方式：

mysql> select Host,User,plugin,authentication_string from mysql.user;    --看下面的root用戶的認證方式和其他用戶都是不一樣的，
+-----------+------------------+-----------------------+------------------------------------------------------------------------+
| Host      | User             | plugin                | authentication_string                                                  |
+-----------+------------------+-----------------------+------------------------------------------------------------------------+
| localhost | mysql.infoschema | mysql_native_password | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE                              |
| localhost | mysql.session    | mysql_native_password | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE                              |
| localhost | mysql.sys        | mysql_native_password | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE                              |
| localhost | root             | caching_sha2_password | $A$005$T?yK{e`l{mrnZd|0iETvMwJ197qvnDXttfzdZX98q6xvFBwXuWd3ioPfnV7 |
+-----------+------------------+-----------------------+------------------------------------------------------------------------+
4 rows in set (0.00 sec)
mysql> ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY '123456';   ---在修改密碼的時候指定密碼加密認證方式
Query OK, 0 rows affected (0.11 sec)
mysql> select Host,User,plugin,authentication_string from mysql.user;  ---再次查看所有用戶都一樣了，和5.7版本一樣
+-----------+------------------+-----------------------+-------------------------------------------+
| Host      | User             | plugin                | authentication_string                     |
+-----------+------------------+-----------------------+-------------------------------------------+
| localhost | mysql.infoschema | mysql_native_password | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE |
| localhost | mysql.session    | mysql_native_password | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE |
| localhost | mysql.sys        | mysql_native_password | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE |
| localhost | root             | mysql_native_password | *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 |
+-----------+------------------+-----------------------+-------------------------------------------+
4 rows in set (0.00 sec)

另外，在MySQL8.0授權和創建用戶更加嚴格了，在MySQL5.7可以使用命令如下：

MySQL [(none)]> grant all privileges on *.* to 'test_user'@'192.168.2.%' identified by '123123'; ----MySQL5.7創建用戶授權的方法，報錯了，

ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'identified by '123123'' at line 1

在MySQL8.0中必須先創建用戶再授權：

MySQL > create user 'test_user'@'%' identified by '123456'; --先創建用戶

Query OK, 0 rows affected (0.03 sec)

MySQL > grant all privileges on *.* to 'test_user'@'%' with grant option; --再授權

Query OK, 0 rows affected (0.05 sec)

MySQL8.0的版本還是有很多變化的，技術在不斷更新所以要努力學習！

MySQL8.0.11 for linux7.2 二進制安裝