Centos7安装MySQL8.0-操作手册

一.Mysql8.0.31安装 (YUM方式)1) 首先删除系统默认或之前可能安装的其他版本的mysql或者mairadb

[root@mysql-8.0 ~]# for i in $(rpm -qa|grep -E "mysql|mariadb");do rpm -e $i --nodeps;done
[root@mysql-8.0 ~]# rm -rf /var/lib/mysql && rm -rf /etc/my.cnf

2) 安装Mysql8.0.31 的yum资源库
mysql80-community-release-el7-7.noarch.rpm
下载地址: https://repo.mysql.com
上传到本地后安装yum源
[root@mysql-8.0 ~]# rpm -ivh mysql80-community-release-el7-7.noarch.rpm
或者直接执行下面的安装命令执行安装
[root@mysql-8.0 ~]# yum localinstall https://repo.mysql.com//mysql80-community-release-el7-7.noarch.rpm
mysql8.0.31的yum源安装完成后会在/etc/yum.repo.d/下生成mysql8.0.31的yum源文件
3) 安装Mysql8.0.31
[root@mysql-8.0 ~]# yum install mysql-community-server

启动MySQL服务器和MySQL的自动启动
[root@mysql-8.0 ~]# systemctl start mysqld
[root@mysql-8.0 ~]# systemctl enable mysqld

4) 使用默认密码初次登录后, 必须要重置密码

查看默认密码, 如下默认密码为"C+wqFWkw#+.W"
[root@mysql-8.0 ~]# grep 'temporary password' /var/log/mysqld.log
2022-11-15T06:34:07.897262Z 5 [Note] [MY-010454] [Server] A temporary password is generated for root@localhost: C+wqFWkw#+.W

[root@mysql-8.0 ~]# mysql -pC+wqFWkw#+.W
Server version 8.0.31
............
mysql> select version();
ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.

报错提示必须要重置初始密码, 下面开始重置mysql登录密码（注意要切换到mysql数据库，使用use mysql）
mysql> use mysql;
ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.

先设置一下复杂的密码，8.0以后的版本默认的密码策略级别高，所以需要设置复杂的密码
mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY 'Aa@123456';
Query OK, 0 rows affected (0.05 sec)

这个其实与validate_password_policy的值有关, mysql8.0版本以后更改了validate_password_policy相关的配置名称, 这跟Mysql5.7有点不一样了.
mysql> set global validate_password.policy=0; //修改完密码后，可以设置密码的策略为0，默认值1。0(LOW)：只校验长度；1(MEDIUM)：校验长度、大小写和特殊字符；2(STRONG)：校验长度、大小写、特殊字符和dictionary_file
Query OK, 0 rows affected (0.00 sec)

mysql> set global validate_password.length=1; //修改密码的长度最短为1
Query OK, 0 rows affected (0.00 sec)

接着再修改密码
mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY '123456';
Query OK, 0 rows affected (0.05 sec)

mysql> flush privileges;
Query OK, 0 rows affected (0.03 sec)

退出, 重新使用新密码登录mysql
[root@mysql-8.0 ~]# mysql -p123456
...........
mysql> select version();
+-----------+
| version() |
+-----------+
| 8.0.31 |
+-----------+
1 row in set (0.00 sec)

查看mysql连接的授权信息
mysql> select host,user,password from mysql.user;
ERROR 1054 (42S22): Unknown column 'password' in 'field list'

上面这是mysql5.6及以下版本的查看命令,
mysql5.7之后的数据库里mysql.user表里已经没有password这个字段了，password字段改成了authentication_string。
mysql> select host,user,authentication_string from mysql.user;
+-----------+------------------+------------------------------------------------------------------------+
| host | user | authentication_string |
+-----------+------------------+------------------------------------------------------------------------+
| localhost | mysql.infoschema | $A$005$THISISACOMBINATIONOFINVALIDSALTANDPASSWORDTHATMUSTNEVERBRBEUSED |
| localhost | mysql.session | $A$005$THISISACOMBINATIONOFINVALIDSALTANDPASSWORDTHATMUSTNEVERBRBEUSED |
| localhost | mysql.sys | $A$005$THISISACOMBINATIONOFINVALIDSALTANDPASSWORDTHATMUSTNEVERBRBEUSED |
| localhost | root | $A$005${7J0=4Dc7Jym8eI/FU4jimKWFvkD9XmoAkF1ca5.Un0bc6zgmPtU.0 |
+-----------+------------------+------------------------------------------------------------------------+
4 rows in set (0.00 sec)

=============================mysql8.0修改用户密码命令================================
mysql> use mysql;
mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY '123456';
mysql> flush privileges;

二. Mysql8.0安装 (二进制方式)

1) 首先删除系统默认或之前可能安装的其他版本的mysql
[root@mysql-8.0 ~]# for i in $(rpm -qa|grep -E "mysql|mariadb");do rpm -e $i --nodeps;done
[root@mysql-8.0 ~]# rm -rf /var/lib/mysql && rm -rf /etc/my.cnf

2) 安装需要的软件包
[root@mysql-8.0 ~]# yum -y install libaio
[root@mysql-8.0 ~]# yum -y install net-tools

3) 下载并安装Mysql8.0.12
链接: https://pan.baidu.com/s/1NXZFDUu8BYfxzXO8obkV2w
提取码: mku9

[root@mysql8-node ~]# groupadd mysql
[root@mysql8-node ~]# useradd -g mysql mysql

[root@mysql8-node ~]# cd /usr/local/src/
[root@mysql-8.0 src]# ll
-rw-r--r-- 1 root root 620389228 Aug 22 2022 mysql8.0.12_bin_centos7.tar.gz
[root@mysql-8.0 src]# tar -zvxf mysql8.0.12_bin_centos7.tar.gz
[root@mysql-8.0 src]# mv mysql /usr/local/
[root@mysql-8.0 src]# chown -R mysql.mysql /usr/local/mysql

[root@mysql-8.0 src]# vim /home/mysql/.bash_profile
export PATH=/usr/local/mysql/bin:/usr/local/mysql/lib:$PATH
[root@mysql-8.0 src]# source /home/mysql/.bash_profile
[root@mysql-8.0 src]# echo "PATH=$PATH:/usr/local/mysql/bin" >> /etc/profile
[root@mysql-8.0 src]# source /etc/profile

4) 创建数据目录
[root@mysql-8.0 src]# mkdir -p /data/mysql/{data,log,binlog,conf,tmp}
[root@mysql-8.0 src]# chown -R mysql.mysql /data/mysql

5) 配置mysql
[root@mysql-8.0 src]# su - mysql
[mysql@mysql-8.0 ~]$ vim /data/mysql/conf/my.cnf
[mysqld]
lower_case_table_names = 1
user = mysql
server_id = 1
port = 3306

default-time-zone = '+08:00'
enforce_gtid_consistency = ON
gtid_mode = ON
binlog_checksum = none
default_authentication_plugin = mysql_native_password //修改默认的密码插件
datadir = /data/mysql/data
pid-file = /data/mysql/tmp/mysqld.pid
socket = /data/mysql/tmp/mysqld.sock
tmpdir = /data/mysql/tmp/
skip-name-resolve = ON
open_files_limit = 65535
table_open_cache = 2000

#################innodb########################
innodb_data_home_dir = /data/mysql/data
innodb_data_file_path = ibdata1:512M;ibdata2:512M:autoextend
innodb_buffer_pool_size = 12000M
innodb_flush_log_at_trx_commit = 1
innodb_io_capacity = 600
innodb_lock_wait_timeout = 120
innodb_log_buffer_size = 8M
innodb_log_file_size = 200M
innodb_log_files_in_group = 3
innodb_max_dirty_pages_pct = 85
innodb_read_io_threads = 8
innodb_write_io_threads = 8
innodb_thread_concurrency = 32
innodb_file_per_table
innodb_rollback_on_timeout

innodb_undo_directory = /data/mysql/data
innodb_log_group_home_dir = /data/mysql/data

###################session###########################
join_buffer_size = 8M
key_buffer_size = 256M
bulk_insert_buffer_size = 8M
max_heap_table_size = 96M
tmp_table_size = 96M
read_buffer_size = 8M
sort_buffer_size = 2M
max_allowed_packet = 64M
read_rnd_buffer_size = 32M

############log set###################
log-error = /data/mysql/log/mysqld.err
log-bin = /data/mysql/binlog/binlog
log_bin_index = /data/mysql/binlog/binlog.index
max_binlog_size = 500M
slow_query_log_file = /data/mysql/log/slow.log
slow_query_log = 1
long_query_time = 10
log_queries_not_using_indexes = ON
log_throttle_queries_not_using_indexes = 10
log_slow_admin_statements = ON
log_output = FILE,TABLE
master_info_file = /data/mysql/binlog/master.info

6) 初始化 (稍等一会儿, 可以到/data/mysql/log/mysqld.err日子里查看初始化过程, 看看有没有error信息)
[mysql@mysql-8.0 ~]$ mysqld --defaults-file=/data/mysql/conf/my.cnf --initialize-insecure --user=mysql

7) 启动mysqld
[mysql@mysql-8.0 ~]$ mysqld_safe --defaults-file=/data/mysql/conf/my.cnf &
[mysql@mysql-8.0 ~]$ lsof -i:3306
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
mysqld 24743 mysql 23u IPv6 23132988 0t0 TCP *:mysql (LISTEN)

8) 登录mysql, 重置密码
本地首次使用sock文件登录mysql是不需要密码的
[mysql@mysql-8.0 ~]# mysql -S /data/mysql/tmp/mysqld.sock
.............
mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY '123456';
Query OK, 0 rows affected (0.07 sec)

mysql> flush privileges;
Query OK, 0 rows affected (0.03 sec)

mysql> select host,user,authentication_string from mysql.user;
+-----------+------------------+------------------------------------------------------------------------+
| host | user | authentication_string |
+-----------+------------------+------------------------------------------------------------------------+
| localhost | mysql.infoschema | $A$005$THISISACOMBINATIONOFINVALIDSALTANDPASSWORDTHATMUSTNEVERBRBEUSED |
| localhost | mysql.session | $A$005$THISISACOMBINATIONOFINVALIDSALTANDPASSWORDTHATMUSTNEVERBRBEUSED |
| localhost | mysql.sys | $A$005$THISISACOMBINATIONOFINVALIDSALTANDPASSWORDTHATMUSTNEVERBRBEUSED |
| localhost | root | *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 |
+-----------+------------------+------------------------------------------------------------------------+
4 rows in set (0.00 sec)

退出, 此时密码重置后, 就不能使用sock文件无密码登录了
[root@mysql-8.0 ~]# mysql -S /data/mysql/tmp/mysqld.sock
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)

[root@mysql-8.0 ~]# mysql -p123456
mysql: [Warning] Using a password on the command line interface can be insecure.
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2)

做sock文件的软链接
[root@mysql-8.0 ~]# ln -s /data/mysql/tmp/mysqld.sock /tmp/mysql.sock

[root@mysql-8.0 ~]# mysql -p123456
或者
[root@mysql-8.0 ~]# mysql -uroot -S /data/mysql/tmp/mysqld.sock -p123456
.............
mysql> select version();
+-----------+
| version() |
+-----------+
| 8.0.12 |
+-----------+
1 row in set (0.00 sec)

#授予用户权限. 必须先要创建用户, 才能授权!!
(创建用户时要带@并指定地址, 则grant授权时的地址就是这个@后面指定的!, 否则grant授权就会报错!)
mysql> create user 'kevin'@'%' identified by '123456';
Query OK, 0 rows affected (0.11 sec)

mysql> grant all privileges on *.* to 'kevin'@'%' with grant option;
Query OK, 0 rows affected (0.21 sec)

mysql> update mysql.user set host='172.16.60.%' where user="kevin";
Query OK, 1 row affected (0.16 sec)
Rows matched: 1 Changed: 1 Warnings: 0

mysql> flush privileges;
Query OK, 0 rows affected (0.05 sec)

mysql> create user 'bobo'@'172.16.60.%' identified by '123456';
Query OK, 0 rows affected (0.09 sec)

mysql> grant all privileges on *.* to 'bobo'@'172.16.60.%';
Query OK, 0 rows affected (0.17 sec)

mysql> flush privileges;
Query OK, 0 rows affected (0.04 sec)

mysql> show grants for kevin@'172.16.60.%';
+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Grants for kevin@172.16.60.% |
+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| GRANT SELECT, INSERT, UPDATE, DELETE, CREATE, DROP, RELOAD, SHUTDOWN, PROCESS, FILE, REFERENCES, INDEX, ALTER, SHOW DATABASES, SUPER, CREATE TEMPORARY TABLES, LOCK TABLES, EXECUTE, REPLICATION SLAVE, REPLICATION CLIENT, CREATE VIEW, SHOW VIEW, CREATE ROUTINE, ALTER ROUTINE, CREATE USER, EVENT, TRIGGER, CREATE TABLESPACE, CREATE ROLE, DROP ROLE ON *.* TO `kevin`@`172.16.60.%` WITH GRANT OPTION |
+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

MySQL单机多实例安装配置 通过上面二进制部署可知, 已经起来一个3306端口的MySQL实例, 现在需要再起来两个实例, 分别为3307, 3308. 操作如下:

创建实例的数据目录
[root@mysql-8.0 ~]# mkdir -p /data/mysql3307/{data,log,binlog,conf,tmp}       
[root@mysql-8.0 ~]# mkdir -p /data/mysql3308/{data,log,binlog,conf,tmp}      
[root@mysql-8.0 ~]# chown -R mysql.mysql /data/mysql3307
[root@mysql-8.0 ~]# chown -R mysql.mysql /data/mysql3308

配置mysql
[root@mysql-8.0 ~]# cp -r /data/mysql/conf/my.cnf /data/mysql3307/conf/
[root@mysql-8.0 ~]# cp -r /data/mysql/conf/my.cnf /data/mysql3308/conf/
[root@mysql-8.0 ~]# sed -i 's#/data/mysql/#/data/mysql3307/#g' /data/mysql3307/conf/my.cnf
[root@mysql-8.0 ~]# sed -i 's#/data/mysql/#/data/mysql3308/#g' /data/mysql3308/conf/my.cnf 
[root@mysql-8.0 ~]# sed -i 's/3306/3307/g' /data/mysql3307/conf/my.cnf 
[root@mysql-8.0 ~]# sed -i 's/3306/3308/g' /data/mysql3308/conf/my.cnf   
[root@mysql-8.0 ~]# chown -R mysql.mysql /data/mysql*

进行初始化两个实例
[root@mysql-8.0 ~]# mysqld --defaults-file=/data/mysql3307/conf/my.cnf  --initialize-insecure  --user=mysql  
[root@mysql-8.0 ~]# mysqld --defaults-file=/data/mysql3308/conf/my.cnf  --initialize-insecure  --user=mysql 

接着启动mysqld
[root@mysql-8.0 ~]# mysqld_safe --defaults-file=/data/mysql3307/conf/my.cnf & 
[root@mysql-8.0 ~]# mysqld_safe --defaults-file=/data/mysql3308/conf/my.cnf & 

[root@mysql-8.0 ~]# ps -ef|grep mysql
mysql    23996     1  0 14:37 ?        00:00:00 /bin/sh /usr/local/mysql/bin/mysqld_safe --defaults-file=/data/mysql/conf/my.cnf
mysql    24743 23996  0 14:38 ?        00:00:17 /usr/local/mysql/bin/mysqld --defaults-file=/data/mysql/conf/my.cnf --basedir=/usr/local/mysql --datadir=/data/mysql/data --plugin-dir=/usr/local/mysql/lib/plugin --log-error=/data/mysql/log/mysqld.err --open-files-limit=65535 --pid-file=/data/mysql/tmp/mysqld.pid --socket=/data/mysql/tmp/mysqld.sock --port=3306
root     30473 23727  0 15:33 pts/0    00:00:00 /bin/sh /usr/local/mysql/bin/mysqld_safe --defaults-file=/data/mysql3307/conf/my.cnf
mysql    31191 30473 17 15:33 pts/0    00:00:02 /usr/local/mysql/bin/mysqld --defaults-file=/data/mysql3307/conf/my.cnf --basedir=/usr/local/mysql --datadir=/data/mysql3307/data --plugin-dir=/usr/local/mysql/lib/plugin --user=mysql --log-error=/data/mysql3307/log/mysqld.err --open-files-limit=65535 --pid-file=/data/mysql3307/tmp/mysqld.pid --socket=/data/mysql3307/tmp/mysqld.sock --port=3307
root     31254 23727  0 15:33 pts/0    00:00:00 /bin/sh /usr/local/mysql/bin/mysqld_safe --defaults-file=/data/mysql3308/conf/my.cnf
mysql    31977 31254 39 15:33 pts/0    00:00:02 /usr/local/mysql/bin/mysqld --defaults-file=/data/mysql3308/conf/my.cnf --basedir=/usr/local/mysql --datadir=/data/mysql3308/data --plugin-dir=/usr/local/mysql/lib/plugin --user=mysql --log-error=/data/mysql3308/log/mysqld.err --open-files-limit=65535 --pid-file=/data/mysql3308/tmp/mysqld.pid --socket=/data/mysql3308/tmp/mysqld.sock --port=3308
root     32044 23727  0 15:34 pts/0    00:00:00 grep --color=auto mysql

[root@mysql-8.0 ~]# lsof -i:3307
COMMAND   PID  USER   FD   TYPE   DEVICE SIZE/OFF NODE NAME
mysqld  31191 mysql   22u  IPv6 23144844      0t0  TCP *:opsession-prxy (LISTEN)
[root@mysql-8.0 ~]# lsof -i:3308
COMMAND   PID  USER   FD   TYPE   DEVICE SIZE/OFF NODE NAME
mysqld  31977 mysql   22u  IPv6 23145727      0t0  TCP *:tns-server (LISTEN)
[root@mysql-8.0 ~]# lsof -i:3306
COMMAND   PID  USER   FD   TYPE   DEVICE SIZE/OFF NODE NAME
mysqld  24743 mysql   23u  IPv6 23132988      0t0  TCP *:mysql (LISTEN)

登录3307端口实例, 并设置密码
[root@mysql-8.0 ~]# mysql -S /data/mysql3307/tmp/mysqld.sock
............
mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY '123456';
Query OK, 0 rows affected (0.11 sec)

mysql> flush privileges;
Query OK, 0 rows affected (0.11 sec)

退出, 使用新密码登录
[root@mysql-8.0 ~]# mysql -uroot -S /data/mysql3307/tmp/mysqld.sock -p123456    
.............
mysql> 

同理, 登录3308端口实例, 并设置密码
[root@mysql-8.0 ~]# mysql -S /data/mysql3308/tmp/mysqld.sock
...........
mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY '123456';
Query OK, 0 rows affected (0.13 sec)

mysql> flush privileges;
Query OK, 0 rows affected (0.03 sec)

退出, 使用新密码登录
[root@mysql-8.0 ~]# mysql -uroot -S /data/mysql3308/tmp/mysqld.sock -p123456
....................
mysql>


==========================================
3306, 3307, 3308三个端口实例的启动命令分别为:
mysqld_safe --defaults-file=/data/mysql/conf/my.cnf & 
mysqld_safe --defaults-file=/data/mysql3307/conf/my.cnf & 
mysqld_safe --defaults-file=/data/mysql3308/conf/my.cnf & 

登录命令分别为:
mysql -uroot -S /data/mysql/tmp/mysqld.sock -p123456
mysql -uroot -S /data/mysql3307/tmp/mysqld.sock -p123456
mysql -uroot -S /data/mysql3308/tmp/mysqld.sock -p123456

三.Mysql8.0使用过程中踩过的一些坑

1) 创建用户和授权

在mysql8.0创建用户和授权和之前不太一样了，其实严格上来讲，也不能说是不一样, 只能说是更严格, mysql8.0需要先创建用户(创建用户时要带@并指定地址, 则grant授权时的地址就是这个@后面指定的!, 否则grant授权就会报错!)和设置密码,然后才能授权。

mysql> create user 'test01'@'%' identified by '123456';
Query OK, 0 rows affected (0.04 sec)

mysql> grant all privileges on *.* to 'test01'@'%' with grant option;    
Query OK, 0 rows affected (0.04 sec)

mysql> create user 'test02'@'%' identified by '123456';     
Query OK, 0 rows affected (0.06 sec)

mysql> grant all privileges on *.* to 'test02'@'%' with grant option;
Query OK, 0 rows affected (0.03 sec)

mysql> flush privileges;
Query OK, 0 rows affected (0.04 sec)

mysql> select host,user,authentication_string from mysql.user;
+-----------+------------------+------------------------------------------------------------------------+
| host      | user             | authentication_string                                                  |
+-----------+------------------+------------------------------------------------------------------------+
| %         | test02             | $A$005$1VY")q?G6<^X@-6LsXrPt5C0TwlTuvHbaOa3sYF0DKViIGoRPuCF8AzwiFcim1  |
| %         | test01            | $A$005$hy`U}ZB#R::rA8W0y2rmwgySqzv0rmR1eTeNDSaXfQPWIsrh7ytbVdi85       |
| localhost | mysql.infoschema | $A$005$THISISACOMBINATIONOFINVALIDSALTANDPASSWORDTHATMUSTNEVERBRBEUSED |
| localhost | mysql.session    | $A$005$THISISACOMBINATIONOFINVALIDSALTANDPASSWORDTHATMUSTNEVERBRBEUSED |
| localhost | mysql.sys        | $A$005$THISISACOMBINATIONOFINVALIDSALTANDPASSWORDTHATMUSTNEVERBRBEUSED |
| localhost | root             | $A$005$/VO_y^7,]6;2qxggBLmJzhA0Qylu5/AHuRScZ/ykKedgZKh/6krOIzPs2       |
+-----------+------------------+------------------------------------------------------------------------+

如果还是用Mysql5.7及之前版本的直接授权的方法, 会有报错:

mysql> grant all privileges on *.* to 'ceshi'@'%' identified by '123456';
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 '123456'' at line 1

2) Mysql8.0默认是不能使用root账号进行远程登录的! root账号只能本地登录!

mysql> select host,user,authentication_string from mysql.user;
+-----------+------------------+------------------------------------------------------------------------+
| host      | user             | authentication_string                                                  |
+-----------+------------------+------------------------------------------------------------------------+
| %         | bobo             | $A$005$1VY")q?G6<^X@-6LsXrPt5C0TwlTuvHbaOa3sYF0DKViIGoRPuCF8AzwiFcim1 |
| %         | kevin            | $A$005$hy`U}ZB#R::rA8W0y2rmwgySqzv0rmR1eTeNDSaXfQPWIsrh7ytbVdi85 |
| localhost | mysql.infoschema | $A$005$THISISACOMBINATIONOFINVALIDSALTANDPASSWORDTHATMUSTNEVERBRBEUSED |
| localhost | mysql.session    | $A$005$THISISACOMBINATIONOFINVALIDSALTANDPASSWORDTHATMUSTNEVERBRBEUSED |
| localhost | mysql.sys        | $A$005$THISISACOMBINATIONOFINVALIDSALTANDPASSWORDTHATMUSTNEVERBRBEUSED |
| localhost | root             | $A$005$/VO_y^7,]6;2qxggBLmJzhA0Qylu5/AHuRScZ/ykKedgZKh/6krOIzPs2 |
+-----------+------------------+------------------------------------------------------------------------+
6 rows in set (0.00 sec)

如果想要远程登录, 则需要进行update更新下root账号的权限
mysql> update mysql.user set host='%' where user="root";
Query OK, 1 row affected (0.10 sec)
Rows matched: 1  Changed: 1  Warnings: 0

mysql> flush privileges;
Query OK, 0 rows affected (0.14 sec)

mysql> select host,user,authentication_string from mysql.user;
+-----------+------------------+------------------------------------------------------------------------+
| host      | user             | authentication_string                                                  |
+-----------+------------------+------------------------------------------------------------------------+
| %         | bobo             | $A$005$1VY")q?G6<^X@-6LsXrPt5C0TwlTuvHbaOa3sYF0DKViIGoRPuCF8AzwiFcim1  |
| %         | kevin            | $A$005$hy`U}ZB#R::rA8W0y2rmwgySqzv0rmR1eTeNDSaXfQPWIsrh7ytbVdi85       |
| %         | root             | $A$005$/VO_y^7,]6;2qxggBLmJzhA0Qylu5/AHuRScZ/ykKedgZKh/6krOIzPs2       |
| localhost | mysql.infoschema | $A$005$THISISACOMBINATIONOFINVALIDSALTANDPASSWORDTHATMUSTNEVERBRBEUSED |
| localhost | mysql.session    | $A$005$THISISACOMBINATIONOFINVALIDSALTANDPASSWORDTHATMUSTNEVERBRBEUSED |
| localhost | mysql.sys        | $A$005$THISISACOMBINATIONOFINVALIDSALTANDPASSWORDTHATMUSTNEVERBRBEUSED |
+-----------+------------------+------------------------------------------------------------------------+
6 rows in set (0.00 sec)

3) 修改root账号权限, 允许root账号远程登录后, 用navicat进行mysql的远程连接时，出现了弹窗报错：

出现这个原因是mysql8 之前的版本中加密规则是mysql_native_password, 而在mysql8之后,加密规则是caching_sha2_password, 解决问题方法有两种:

1) 一种是升级navicat驱动;

2) 一种是把mysql用户登录密码加密规则还原成mysql_native_password;

3)在配置文件中，修改：default_authentication_plugin=mysql_native_password，然后重启mysql服务，新配置只对以后新添加的用户生效，之前新建的用户不能生效，需要手动修改已经创建的用户的加密规则。

这里选择第二种方法来解决:

#修改加密规则 
mysql> ALTER USER 'root'@'%' IDENTIFIED BY '123456' PASSWORD EXPIRE NEVER;        
Query OK, 0 rows affected (0.16 sec)

#更新一下用户的密码 
mysql> ALTER USER 'root'@'%' IDENTIFIED WITH mysql_native_password BY '123456';
Query OK, 0 rows affected (0.08 sec)

#刷新权限 
mysql> FLUSH PRIVILEGES;
Query OK, 0 rows affected (0.03 sec)

4) 修改默认编码方式

mysql8.0默认编码方式为utf8mb4，因此使用时不需要修改，可使用如下命令查看：
mysql > SHOW VARIABLES WHERE Variable_name LIKE 'character_set_%' OR Variable_name LIKE 'collation%';

如果需要修改其他编码方式，比如需要修改为utf8mb4，可以使用如下方式：
修改mysql配置文件my.cnf, 找到后请在以下三部分里添加如下内容：
[client]
default-character-set = utf8mb4
[mysql]
default-character-set = utf8mb4
[mysqld]
character-set-client-handshake = FALSE
character-set-server = utf8mb4
collation-server = utf8mb4_unicode_ci
init_connect='SET NAMES utf8mb4'

然后重启mysqld服务即可, 其中:
character_set_client  (客户端来源数据使用的字符集)
character_set_connection     (连接层字符集)
character_set_database   (当前选中数据库的默认字符集)
character_set_results (查询结果字符集)
character_set_server (默认的内部操作字符集)

========================================
数据库连接参数中:
characterEncoding=utf8 会被自动识别为utf8mb4，也可以不加这个参数，会自动检测。
而autoReconnect=true 是必须加上的。

5) 部分参数配置查询命令

#查询mysql最大连接数设置
mysql> show global variables like 'max_conn%';
mysql> SELECT @@MAX_CONNECTIONS AS 'Max Connections';

# 查看最大链接数
mysql> show global status like 'Max_used_connections';

# 查看慢查询日志是否开启以及日志位置
mysql> show variables like 'slow_query%';

# 查看慢查询日志超时记录时间
mysql> show variables like 'long_query_time';

# 查看链接创建以及现在正在链接数
mysql> show status like 'Threads%';

# 查看数据库当前链接
mysql> show processlist;

# 查看数据库配置
mysql> show variables like '%quer%';

posted @ 2022-11-15 15:19 粉色纽扣阅读(548) 评论(0) 编辑收藏举报

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