mysql运维

1、msyqlLinux通用二进制安装

1. MySQL :: Download MySQL Community Server (Archived Versions)https://downloads.mysql.com/archives/community/https://downloads.mysql.com/archives/community/https://downloads.mysql.com/archives/community/https://downloads.mysql.com/archives/community/https://downloads.mysql.com/archives/community/https://downloads.mysql.com/archives/community/https://downloads.mysql.com/archives/community/https://downloads.mysql.com/archives/community/https://downloads.mysql.com/archives/community/下载8.0.28

2.把二进制包放到Linux下

# 添加mysql组
$> groupadd mysql
# 增加mysql用户，把-g mysql组加到mysql用户中,-s 指定用户的登录shell,/bin/false创建没有服务器登录权限的用户 主机,-r 创建一个系统用户，系统用户的 UID 通常小于 1000。
$> useradd -r -g mysql -s /bin/false mysql
$> cd /usr/local
# 把mysql解压到这个目录下
$> tar xvf /path/to/mysql-VERSION-OS.tar.xz
# 创建硬链接mysql
$> ln -s full-path-to-mysql-VERSION-OS mysql
$> cd mysql
$> mkdir mysql-files
$> chown mysql:mysql mysql-files
$> chmod 750 mysql-files
# 初始化数据库
$> bin/mysqld --initialize --user=mysql
# 启动数据库服务端
$> bin/mysqld_safe --user=mysql &
# Next command is optional
$> cp support-files/mysql.server /etc/init.d/mysql.server

初始化数据库时可能会出现问题

是因为找不到 libaio.so.1这个库

查看系统是否有libaio.so 但不是 libaio.so.1

root@hwz-VMware-Virtual-Platform:/usr/local/mysql# ldconfig -p | grep libaiolibaio.so.1t64 (libc6,x86-64) => /lib/x86_64-linux-gnu/libaio.so.1t64libaio.so (libc6,x86-64) => /lib/x86_64-linux-gnu/libaio.so

查看libaio.so位置

root@hwz-VMware-Virtual-Platform:/usr/local/mysql# find /usr -name libaio.so*
/usr/lib/x86_64-linux-gnu/libaio.so.1t64.0.2
/usr/lib/x86_64-linux-gnu/libaio.so.1t64
/usr/lib/x86_64-linux-gnu/libaio.so

创建软链接链接到libaio.so.1

root@hwz-VMware-Virtual-Platform:/usr/local/mysql# ln -s /usr/lib/x86_64-linux-gnu/libaio.so.1t64.0.2 /usr/lib/x86_64-linux-gnu/libaio.so.1

再次初始化就没问题了，后面他会给你个root的临时密码

2025-01-23T08:37:26.842753Z 0 [System] [MY-013169] [Server] /usr/local/mysql-8.0.28-linux-glibc2.12-x86_64/bin/mysqld (mysqld 8.0.28) initializing of server in progress as process 14334
2025-01-23T08:37:26.897078Z 1 [System] [MY-013576] [InnoDB] InnoDB initialization has started.
2025-01-23T08:37:27.685107Z 1 [System] [MY-013577] [InnoDB] InnoDB initialization has ended.
2025-01-23T08:37:29.432879Z 6 [Note] [MY-010454] [Server] A temporary password is generated for root@localhost: t8g,pkplN4YI

启动后用mysql客户端连接测试一下

root@hwz-VMware-Virtual-Platform:/usr/local/mysql# bin/mysql -u root -p
bin/mysql: error while loading shared libraries: libtinfo.so.5: cannot open shared object file: No such file or directory

是缺少 libtinfo.so.5原因

查找一下有没有这个库

root@hwz-VMware-Virtual-Platform:/usr/local/mysql# ldconfig -p | grep libtinfolibtinfo.so.6 (libc6,x86-64) => /lib/x86_64-linux-gnu/libtinfo.so.6

发现libtinfo.so.6但没有 libtinfo.so.5

也可以用6代替5

找到6库位置

root@hwz-VMware-Virtual-Platform:/usr/local/mysql# find /usr -name libtinfo.so*
/usr/lib/x86_64-linux-gnu/libtinfo.so.6.5
/usr/lib/x86_64-linux-gnu/libtinfo.so.6

root@hwz-VMware-Virtual-Platform:/usr/local/mysql# ln -n /usr/lib/x86_64-linux-gnu/libtinfo.so.6.5 /usr/lib/x86_64-linux-gnu/libtinfo.so.5

使用初始密码登录成功

root@hwz-VMware-Virtual-Platform:/usr/local/mysql# bin/mysql -u root -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 14
Server version: 8.0.28Copyright (c) 2000, 2022, Oracle and/or its affiliates.Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.mysql> show databases;
ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.
mysql>

他要你改密码后才能操作

mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY 'root-password';

这时应该可以正常操作数据库了。

额外的配置

为了可以直接使用mysql命令，不用到/usr/local/mysql/bin找命令，可以mysql的命令添加到环境变量中

vim ~/.bashrc# 在文件最后加上export PATH=$PATH:/usr/local/mysql/binsource ~/.bashrc

使用systemctl管理MySQL服务

在/etc/systemd/system/mysql.service写入下面配置

[Unit]
Description=MySQL Server
After=network.target[Service]
User=mysql
Group=mysql
ExecStart=/usr/local/mysql/bin/mysqld --defaults-file=/etc/mysql/my.cnf
ExecStop=/usr/local/mysql/bin/mysqladmin shutdown
Restart=on-failure[Install]
WantedBy=multi-user.target

systemctl配置文件更改需要使用命令刷新一下配置

systemctl daemon-reload

配置文件/etc/mysql/my.cnf

[client]
user=root
password=xxx    # 配置了这个默认登录root不用输入密码[mysql]
prompt=(\\u@\\h) [\\d]>\\_    # 更改MySQL客户端命令>前面显示内容[mysqld]
port=3306
user=mysql
datadir=/usr/local/mysql/data
log_error=error.log

如果之前开启过MySQL需要使用命令mysqladmin shutdown关闭 MySQL

查看mysql进程是否存在

root@hwz-VMware-Virtual-Platform:/etc/mysql# ps -ef | grep mysql
mysql      18982       1  0 21:22 ?        00:00:05 /usr/local/mysql/bin/mysqld --defaults-file=/etc/mysql/my.cnf
root       19061    3897  0 21:39 pts/2    00:00:00 grep --color=auto mysql

systemctl start mysql # 启动MySQL
systemctl stop mysql # 关闭MySQL
systemctl status mysql # 查看MySQL服务状态

额外注意点

1.启动时如果不特定指定配置文件位置，MySQL启动时会按这几个配置文件顺序读取/etc/my.cnf /etc/mysql/my.cnf /usr/local/mysql/etc/my.cnf ~/.my.cnf

root@hwz-VMware-Virtual-Platform:~# mysql --help | grep my.cnforder of preference, my.cnf, $MYSQL_TCP_PORT,
/etc/my.cnf /etc/mysql/my.cnf /usr/local/mysql/etc/my.cnf ~/.my.cnf

后面的配置文件配置会覆盖前面的配置文件配置

一般配置文件都放在/etc/下，然而/etc/mysql/my.cnf可读性好点，所以推荐放在/etc/mysql/my.cnf

2.前面配置systemctl配置时启动命令为啥不用mysqld_safe而是用mysqld来启动MySQL？

因为mysqld_safe是一个守护进程

这里我使用mysqld_safe启动MySQL会发现它其实是启动了两个进程，一个是mysqld_safe，一个是mysqld,本质还是用mysqld启动MySQL，mysqld_safe是用来监视mysqld的，mysqld挂掉了会自动启动，这里可以使用kill -9 掉mysqld来测试。

root@hwz-VMware-Virtual-Platform:/etc/mysql# mysqld_safe --user=mysql &
[1] 19086
root@hwz-VMware-Virtual-Platform:/etc/mysql# 2025-01-25T13:46:08.647339Z mysqld_safe Logging to '/usr/local/mysql/data/error.log'.
2025-01-25T13:46:08.700221Z mysqld_safe Starting mysqld daemon with databases from /usr/local/mysql/dataroot@hwz-VMware-Virtual-Platform:/etc/mysql# ps -ef | grep mysql
root       19086    3897  0 21:46 pts/2    00:00:00 /bin/sh /usr/local/mysql/bin/mysqld_safe --user=mysql
mysql      19210   19086 15 21:46 pts/2    00:00:00 /usr/local/mysql/bin/mysqld --basedir=/usr/local/mysql --datadir=/usr/local/mysql/data --plugin-dir=/usr/local/mysql/lib/plugin --user=mysq --log-error=error.log --pid-file=hwz-VMware-Virtual-Platform.pid --port=3306
root       19258    3897  0 21:46 pts/2    00:00:00 grep --color=auto mysql

systemctl本身可以配置守护进程，自然不需要mysqld_safe

1.1 忘记root密码

忘记root密码怎么修改root密码？

原理：跳过连接层的验证用户功能，不让mysql启动加载授权表

1.停掉mysql

root@hwz-VMware-Virtual-Platform:~# systemctl stop mysql

2.使用mysqld_safe加关闭授权功能参数启动MySQL ，关闭tcp/ip连接，然后随便一个写个用户都可以登录上

root@hwz-VMware-Virtual-Platform:~# mysqld_safe --skip-grant-tables --skip-networking &
[1] 4150
root@hwz-VMware-Virtual-Platform:~# 2025-02-03T04:12:03.405924Z mysqld_safe Logging to '/usr/local/mysql/data/error.log'.
2025-02-03T04:12:03.459742Z mysqld_safe Starting mysqld daemon with databases from /usr/local/mysql/dataroot@hwz-VMware-Virtual-Platform:~# mysql -uxxxxx -pxxxxx
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 9
Server version: 8.0.28 MySQL Community Server - GPLCopyright (c) 2000, 2022, Oracle and/or its affiliates.Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.(xxxxx@localhost) [(none)]>

3.加载授权表（启动时跳过加载授权表，但是修改密码需要授权表，所以启动后加载授权表）

(xxxxx@localhost) [(none)]> flush privileges;
Query OK, 0 rows affected (0.02 sec)

3.修改root用户密码

(xxxxx@localhost) [(none)]> alter user root@'localhost' identified by '123456';
Query OK, 0 rows affected (0.01 sec)

4.重启MySQL

先关闭mysql_safe方式启动

root@hwz-VMware-Virtual-Platform:~# mysqladmin -uroot -p123456 shutdown

root@hwz-VMware-Virtual-Platform:~# systemctl restart mysql

1.2 ssl客户端加密连接

8.0版本默认开启ssl，have_openssl、have_ssl都为yes

(root@localhost) [mysql]> show variables like '%ssl%';
+-------------------------------------+-----------------+
| Variable_name                       | Value           |
+-------------------------------------+-----------------+
| admin_ssl_ca                        |                 |
| admin_ssl_capath                    |                 |
| admin_ssl_cert                      |                 |
| admin_ssl_cipher                    |                 |
| admin_ssl_crl                       |                 |
| admin_ssl_crlpath                   |                 |
| admin_ssl_key                       |                 |
| have_openssl                        | YES             |
| have_ssl                            | YES             |
| mysqlx_ssl_ca                       |                 |
| mysqlx_ssl_capath                   |                 |
| mysqlx_ssl_cert                     |                 |
| mysqlx_ssl_cipher                   |                 |
| mysqlx_ssl_crl                      |                 |
| mysqlx_ssl_crlpath                  |                 |
| mysqlx_ssl_key                      |                 |
| performance_schema_show_processlist | OFF             |
| ssl_ca                              | ca.pem          |
| ssl_capath                          |                 |
| ssl_cert                            | server-cert.pem |
| ssl_cipher                          |                 |
| ssl_crl                             |                 |
| ssl_crlpath                         |                 |
| ssl_fips_mode                       | OFF             |
| ssl_key                             | server-key.pem  |
+-------------------------------------+-----------------+
25 rows in set (0.01 sec)

默认已经生成SSL 证书和密钥在数据目录下

用户可以手动调用 mysql_ssl_rsa_setup 实用程序（从 MySQL 8.0.34 开始已弃用）,之后版本数据库启动时如果SSL 证书和密钥不存在则自动生成。

如果存在这些文件中的任何一个，mysql_ssl_rsa_setup 不会创建 SSL 文件。

ca.pem 自签名 CA 证书
ca-key.pem CA 私有密钥
server-cert.pem 服务器证书
server-key.pem 服务器私钥
client-cert.pem 客户端证书
client-key.pem 客户端私钥

RSA 文件

private_key.pem 私钥.pem 文件，私钥/公钥对的私有成员
public_key.pem 公共成员，属于私钥/公钥对

1.2.1 win客户端navicat ssl加密连接上数据库

1.关闭mysql所在服务器防火窗或者开放3306端口

2.添加一个外网段可以访问mysql的用户

这个ip是我Navicat所在机器ip

(root@localhost) [mysql]> create user root@'172.20.10.1' identified by '123456';
Query OK, 0 rows affected (0.01 sec)

创建用户必须要ssl加密才能登录

(root@localhost) [mysql]> create user root@'172.20.10.1' identified by '123456' REQUIRE X509;
Query OK, 0 rows affected (0.01 sec)

或者SET PERSIST require_secure_transport=ON;设置所以客户端连接都需要ssl

连接上了但只看到一个数据库说明没有权限

3。授予权限给这个用户

(root@localhost) [mysql]> grant all on *.* to root@'172.20.10.1';
Query OK, 0 rows affected (0.01 sec)

重新连接就显示全部数据库了

4.使用ssl方式连接

拿出client-cert.pem 客户端证书 client-key.pem 客户端私钥到客户端机器那边。

验证当前连接是否使用了ssl加密连接，不为空则是使用了ssl加密连接

SHOW SESSION STATUS LIKE 'Ssl_cipher';

2.MySQL的配置参数

查看某个参数可用通配符

show variables like 'data%';

变量可分为

按作用范围分（不标明默认是会话变量）
- session会话变量（只影响当前会话）
- global全局变量（影响所有会话）

(root@localhost) [(none)]> set session long_query_time=2-> ;
Query OK, 0 rows affected (0.00 sec)(root@localhost) [(none)]> show variables like 'long_query_time';
+-----------------+----------+
| Variable_name   | Value    |
+-----------------+----------+
| long_query_time | 2.000000 |
+-----------------+----------+
1 row in set (0.01 sec)(root@localhost) [(none)]> set long_query_time=4;
Query OK, 0 rows affected (0.00 sec)(root@localhost) [(none)]> show variables like 'long_query_time';
+-----------------+----------+
| Variable_name   | Value    |
+-----------------+----------+
| long_query_time | 4.000000 |
+-----------------+----------+
1 row in set (0.00 sec)(root@localhost) [(none)]> set global long_query_time=6;
Query OK, 0 rows affected (0.00 sec)(root@localhost) [(none)]> show variables like 'long_query_time';
+-----------------+----------+
| Variable_name   | Value    |
+-----------------+----------+
| long_query_time | 4.000000 |
+-----------------+----------+
1 row in set (0.00 sec)
(root@localhost) [(none)]> set global long_query_time=6;
Query OK, 0 rows affected (0.00 sec)(root@localhost) [(none)]> show variables like 'long_query_time';
+-----------------+----------+
| Variable_name   | Value    |
+-----------------+----------+
| long_query_time | 4.000000 |
+-----------------+----------+
1 row in set (0.00 sec)(root@localhost) [(none)]> set global long_query_time=8;
Query OK, 0 rows affected (0.00 sec)(root@localhost) [(none)]> show global variables like 'long_query_time';
+-----------------+----------+
| Variable_name   | Value    |
+-----------------+----------+
| long_query_time | 8.000000 |
+-----------------+----------+
1 row in set (0.01 sec)

需要注意的是一个会话set global后，有另外一个会话在set global前打开的这个会话，那直接show variables是不会读取到set global后的值的，show global variables可以读取到，你需要重新打开这个会话show variables才会读取到set global后的值。

查看其他会话的变量值

(root@localhost) [performance_schema]> show tables like '%variables%';
+--------------------------------------------+
| Tables_in_performance_schema (%variables%) |
+--------------------------------------------+
| global_variables                           |
| persisted_variables                        |
| session_variables                          |
| user_variables_by_thread                   |
| variables_by_thread                        |
| variables_info                             |
+--------------------------------------------+
6 rows in set (0.00 sec)(root@localhost) [performance_schema]> select * from variables_by_thread where VARIABLE_NAME='long_query_time';
+-----------+-----------------+----------------+
| THREAD_ID | VARIABLE_NAME   | VARIABLE_VALUE |
+-----------+-----------------+----------------+
|        47 | long_query_time | 10.000000      |
|        48 | long_query_time | 8.000000       |
+-----------+-----------------+----------------+
2 rows in set (0.00 sec)

这里可以看到一个是10是我当前会话的 long_query_time的值，另外一个8是另外一个会话设置的值

按类型分
- 可修改变量
- 只读变量（mysql运行中不能修改这种变量比如datadir变量）

MySQL ：： MySQL 8.0 参考手册：： 7.1.8 服务器系统变量

可以查看参数是否是可修改的变量，Dynamic为yes的变量可修改

3.用户权限管理

创建用户

create user 'hwz'@'192.168.1.%' identified by '123456';

删除用户

drop user 'hwz'@'192.168.1.%';

修改用户密码

(root@localhost) [mysql]> alter user 'hwz'@'localhost' identified by '1234';
Query OK, 0 rows affected (0.01 sec)

查看创建的用户

(root@localhost) [mysql]> show create user 'hwz'@'localhost'\G
*************************** 1. row ***************************
CREATE USER for hwz@localhost: CREATE USER `hwz`@`localhost` IDENTIFIED WITH 'caching_sha2_password' AS '$A$005$\\F]4\\L~dQ>A\n\'MP~wsWQWtSMTdbwDCdYV0qIKuWUr.2DKpaWruXUVBb3CSlA' REQUIRE NONE PASSWORD EXPIRE DEFAULT ACCOUNT UNLOCK PASSWORD HISTORY DEFAULT PASSWORD REUSE INTERVAL DEFAULT PASSWORD REQUIRE CURRENT DEFAULT

用户上锁

(root@localhost) [(none)]> alter user hwz@'localhost' account lock;
Query OK, 0 rows affected (0.01 sec)(root@localhost) [(none)]> select user,host,account_locked from mysql.user;
+------------------+-------------+----------------+
| user             | host        | account_locked |
+------------------+-------------+----------------+
| hwz              | 192.168.1.% | N              |
| hwz              | localhost   | Y              |
| mysql.infoschema | localhost   | Y              |
| mysql.session    | localhost   | Y              |
| mysql.sys        | localhost   | Y              |
| root             | localhost   | N              |
+------------------+-------------+----------------+
6 rows in set (0.00 sec)

用户解锁

(root@localhost) [(none)]> alter user hwz@'localhost' account unlock;
Query OK, 0 rows affected (0.00 sec)

查看所有的用户

(root@localhost) [mysql]> select host,user from user;
+-------------+------------------+
| host        | user             |
+-------------+------------------+
| 192.168.1.% | hwz              |
| localhost   | hwz              |
| localhost   | mysql.infoschema |
| localhost   | mysql.session    |
| localhost   | mysql.sys        |
| localhost   | root             |
+-------------+------------------+
6 rows in set (0.00 sec)

授予权限

语法：grant 权限 on 权限级别 to 用户;

权限级别有四种：

*.* : 全库级别 ----->管理员 --->mysql.user
test.*：单库级别 ----->业务层面 ------>mysql.db
test.t1：单表级别 ------->mysql.tables_priv
select(id,name) ：列级别 --------->mysql.columns_priv

# 授予权限前不能看到mysql数据库
(hwz@localhost) [(none)]> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
+--------------------+# 使用root账号授权给hwz账号查看mysql数据库所有表的权限
(root@localhost) [mysql]> grant select on mysql.* to 'hwz'@'localhost';
Query OK, 0 rows affected (0.01 sec)# 授予权限后
(hwz@localhost) [(none)]> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
+--------------------+

授予权限同时授予他的权限授予别人

(root@localhost) [mysql]> grant select,insert on mysql.* to 'hwz'@'localhost' with grant option; 
Query OK, 0 rows affected (0.01 sec)(root@localhost) [mysql]> show grants for 'hwz'@'localhost';
+--------------------------------------------------------------------------+
| Grants for hwz@localhost                                                 |
+--------------------------------------------------------------------------+
| GRANT USAGE ON *.* TO `hwz`@`localhost`                                  |
| GRANT SELECT, INSERT ON `mysql`.* TO `hwz`@`localhost` WITH GRANT OPTION |
+--------------------------------------------------------------------------+
2 rows in set (0.00 sec)

查看当前用户权限

(hwz@localhost) [(none)]> show grants;
+-----------------------------------------+
| Grants for hwz@localhost                |
+-----------------------------------------+
| GRANT USAGE ON *.* TO `hwz`@`localhost` |
+-----------------------------------------+

查看别的用户权限

(root@localhost) [mysql]> show grants for 'hwz'@'localhost';
+-----------------------------------------+
| Grants for hwz@localhost                |
+-----------------------------------------+
| GRANT USAGE ON *.* TO `hwz`@`localhost` |
+-----------------------------------------+

通过权限表查看用户权限

# 这里授权hwz用户能只能查询test库的user表的name字段
(root@localhost) [test]> grant select(name) on test.user to hwz@'localhost';
Query OK, 0 rows affected (0.01 sec)# 可以通过查询mysql.columns_priv查询到该权限，第三个即是
(root@localhost) [mysql]> select * from mysql.columns_priv where user='hwz'\G
*************************** 1. row ***************************Host: localhostDb: mysqlUser: hwzTable_name: user
Column_name: hostTimestamp: 2025-01-28 22:35:17
Column_priv: Select
*************************** 2. row ***************************Host: localhostDb: mysqlUser: hwzTable_name: user
Column_name: userTimestamp: 2025-01-28 22:35:17
Column_priv: Select
*************************** 3. row ***************************Host: localhostDb: testUser: hwzTable_name: user
Column_name: nameTimestamp: 2025-02-03 15:51:27
Column_priv: Select
3 rows in set (0.00 sec)

刚创建的用户只有USAGE权限，相当于没有权限，只能登录

MySQL ：： MySQL 8.0 参考手册：： MySQL 提供的 8.2.2 权限查看所有详细的权限和说明

查看有哪些权限

(root@localhost) [(none)]> show privileges;

收回权限

(root@localhost) [mysql]> revoke select on mysql.* from 'hwz'@'localhost';
Query OK, 0 rows affected (0.01 sec)(root@localhost) [mysql]> show grants for 'hwz'@'localhost';
+-----------------------------------------+
| Grants for hwz@localhost                |
+-----------------------------------------+
| GRANT USAGE ON *.* TO `hwz`@`localhost` |
+-----------------------------------------+

3.1 角色创建和授权

8.0后社区版本才有角色授权

(root@localhost) [mysql]> create role dev_role@'localhost';
Query OK, 0 rows affected (0.02 sec)(root@localhost) [mysql]> grant select,update,insert on test.* to dev_role@'localhost';
Query OK, 0 rows affected (0.00 sec)(root@localhost) [mysql]> create user dev_user@'localhost' identified by '123456';
Query OK, 0 rows affected (0.00 sec)(root@localhost) [mysql]> grant dev_role@'localhost' to dev_user@'localhost';
Query OK, 0 rows affected (0.01 sec)

查看角色

(root@localhost) [mysql]> select * from mysql.role_edges;
+-----------+-----------+-----------+----------+-------------------+
| FROM_HOST | FROM_USER | TO_HOST   | TO_USER  | WITH_ADMIN_OPTION |
+-----------+-----------+-----------+----------+-------------------+
| localhost | dev_role  | localhost | dev_user | N                 |
+-----------+-----------+-----------+----------+-------------------+
1 row in set (0.00 sec)

角色也相当于一个上锁的用户（不能登陆）

(root@localhost) [mysql]> select user,host,authentication_string,account_locked from mysql.user\G
*************************** 2. row ***************************user: dev_rolehost: localhost
authentication_string: account_locked: Y

还可以这样查询用户权限

(root@localhost) [mysql]> select * from information_schema.user_privileges;

3.2 激活角色

向角色授予权限后默认是没有激活角色的。

登录上被授予角色的用户查看当前会话激活的角色，NONE即是没有。

(dev_user2@localhost) [test]> SELECT CURRENT_ROLE();
+----------------+
| CURRENT_ROLE() |
+----------------+
| NONE           |
+----------------+
1 row in set (0.00 sec)

有三种方法激活角色

1. 设置默认激活的角色。当用户登录上时会自动激活默认角色。

设置默认将所有的授予的角色激活

(root@localhost) [mysql]> set default role all to dev_user2@'localhost';
Query OK, 0 rows affected (0.01 sec)

我这里授予了两个角色，所以默认有两个，你也可以默认激活指定一个

(dev_user2@localhost) [(none)]> SELECT CURRENT_ROLE();
+---------------------------------+
| CURRENT_ROLE()                  |
+---------------------------------+
| `dev_role2`@`%`,`dev_role3`@`%` |
+---------------------------------+
1 row in set (0.00 sec)

2.当前会话手动激活指定角色。

(dev_user2@localhost) [(none)]> set role dev_role3;
Query OK, 0 rows affected (0.00 sec)(dev_user2@localhost) [(none)]> SELECT CURRENT_ROLE();
+-----------------+
| CURRENT_ROLE()  |
+-----------------+
| `dev_role3`@`%` |
+-----------------+
1 row in set (0.00 sec)

还有种方式激活所有排查指定角色

(dev_user2@localhost) [(none)]> set role all except dev_role3;
Query OK, 0 rows affected (0.01 sec)(dev_user2@localhost) [(none)]> SELECT CURRENT_ROLE();
+-----------------+
| CURRENT_ROLE()  |
+-----------------+
| `dev_role2`@`%` |
+-----------------+
1 row in set (0.00 sec)

3.开启系统参数activate-all-roles-on-login登录自动激活所有授予的角色。

(root@localhost) [mysql]> show variables like 'activate_all_roles_on_login';
+-----------------------------+-------+
| Variable_name               | Value |
+-----------------------------+-------+
| activate_all_roles_on_login | OFF   |
+-----------------------------+-------+
1 row in set (0.01 sec)(root@localhost) [mysql]> SET GLOBAL activate_all_roles_on_login=ON;
Query OK, 0 rows affected (0.00 sec)(root@localhost) [mysql]> show variables like 'activate_all_roles_on_login';
+-----------------------------+-------+
| Variable_name               | Value |
+-----------------------------+-------+
| activate_all_roles_on_login | ON    |
+-----------------------------+-------+
1 row in set (0.00 sec)

3.3 回收角色

(root@localhost) [mysql]> show grants for hwz@'localhost';
+----------------------------------------------------------------------+
| Grants for hwz@localhost                                             |
+----------------------------------------------------------------------+
| GRANT USAGE ON *.* TO `hwz`@`localhost`                              |
| GRANT INDEX ON `mysql`.* TO `hwz`@`localhost`                        |
| GRANT SELECT (`host`, `user`) ON `mysql`.`user` TO `hwz`@`localhost` |
| GRANT SELECT (`name`) ON `test`.`user` TO `hwz`@`localhost`          |
| GRANT `dev_role2`@`%` TO `hwz`@`localhost`                           |
+----------------------------------------------------------------------+
5 rows in set (0.00 sec)(root@localhost) [mysql]> revoke dev_role2 from hwz@'localhost';
Query OK, 0 rows affected (0.00 sec)

4、

常用命令

1、linux命令

查看某参数的默认值或者官方解释
mysqld --help --verbose | grep defaults-file

2、SQL命令

查找某个配置变量的值

(root@localhost) [(none)]> show variables like 'data%';
+---------------+------------------------+
| Variable_name | Value                  |
+---------------+------------------------+
| datadir       | /usr/local/mysql/data/ |
+---------------+------------------------+
1 row in set (0.01 sec)

查看告警

show warnings;

查看表结构

desc table_name;

查看当前连接服务端的状态

(root@localhost) [mysql]> status
--------------
mysql  Ver 8.0.28 for Linux on x86_64 (MySQL Community Server - GPL)Connection id:		8
Current database:	mysql
Current user:		root@localhost
SSL:			Not in use
Current pager:		stdout
Using outfile:		''
Using delimiter:	;
Server version:		8.0.28 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:		/tmp/mysql.sock
Binary data as:		Hexadecimal
Uptime:			8 hours 44 min 31 secThreads: 3  Questions: 235  Slow queries: 0  Opens: 260  Flush tables: 3  Open tables: 179  Queries per second avg: 0.007
--------------(root@localhost) [mysql]> \s
--------------
mysql  Ver 8.0.28 for Linux on x86_64 (MySQL Community Server - GPL)Connection id:		8
Current database:	mysql
Current user:		root@localhost
SSL:			Not in use
Current pager:		stdout
Using outfile:		''
Using delimiter:	;
Server version:		8.0.28 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:		/tmp/mysql.sock
Binary data as:		Hexadecimal
Uptime:			8 hours 44 min 38 secThreads: 3  Questions: 238  Slow queries: 0  Opens: 260  Flush tables: 3  Open tables: 179  Queries per second avg: 0.007
--------------

查看是否开启ssl连接，主要看have_openssl为yes即为开启（8.x版本默认开启）

(root@localhost) [mysql]> show variables like '%ssl%';
+-------------------------------------+-----------------+
| Variable_name                       | Value           |
+-------------------------------------+-----------------+
| admin_ssl_ca                        |                 |
| admin_ssl_capath                    |                 |
| admin_ssl_cert                      |                 |
| admin_ssl_cipher                    |                 |
| admin_ssl_crl                       |                 |
| admin_ssl_crlpath                   |                 |
| admin_ssl_key                       |                 |
| have_openssl                        | YES             |
| have_ssl                            | YES             |
| mysqlx_ssl_ca                       |                 |
| mysqlx_ssl_capath                   |                 |
| mysqlx_ssl_cert                     |                 |
| mysqlx_ssl_cipher                   |                 |
| mysqlx_ssl_crl                      |                 |
| mysqlx_ssl_crlpath                  |                 |
| mysqlx_ssl_key                      |                 |
| performance_schema_show_processlist | OFF             |
| ssl_ca                              | ca.pem          |
| ssl_capath                          |                 |
| ssl_cert                            | server-cert.pem |
| ssl_cipher                          |                 |
| ssl_crl                             |                 |
| ssl_crlpath                         |                 |
| ssl_fips_mode                       | OFF             |
| ssl_key                             | server-key.pem  |
+-------------------------------------+-----------------+

查看前台连接线程

(root@localhost) [(none)]> show processList;
+----+-----------------+-----------+------+---------+------+------------------------+------------------+
| Id | User            | Host      | db   | Command | Time | State                  | Info             |
+----+-----------------+-----------+------+---------+------+------------------------+------------------+
|  5 | event_scheduler | localhost | NULL | Daemon  |  131 | Waiting on empty queue | NULL             |
|  8 | root            | localhost | NULL | Query   |    0 | init                   | show processList |
+----+-----------------+-----------+------+---------+------+------------------------+------------------+
2 rows in set (0.00 sec)

查看后台在执行的线程（像io线程，SQL线程。。。。）

(root@localhost) [(none)]> select * from performance_schema.threads\G
*************************** 1. row ***************************THREAD_ID: 1NAME: thread/sql/mainTYPE: BACKGROUNDPROCESSLIST_ID: NULLPROCESSLIST_USER: NULLPROCESSLIST_HOST: NULLPROCESSLIST_DB: mysql
PROCESSLIST_COMMAND: NULLPROCESSLIST_TIME: 565PROCESSLIST_STATE: NULLPROCESSLIST_INFO: NULLPARENT_THREAD_ID: NULLROLE: NULLINSTRUMENTED: YESHISTORY: YESCONNECTION_TYPE: NULLTHREAD_OS_ID: 4620RESOURCE_GROUP: SYS_default
*************************** 2. row ***************************THREAD_ID: 3NAME: thread/innodb/io_ibuf_threadTYPE: BACKGROUNDPROCESSLIST_ID: NULLPROCESSLIST_USER: NULLPROCESSLIST_HOST: NULLPROCESSLIST_DB: NULL
PROCESSLIST_COMMAND: NULLPROCESSLIST_TIME: NULLPROCESSLIST_STATE: NULLPROCESSLIST_INFO: NULLPARENT_THREAD_ID: NULLROLE: NULLINSTRUMENTED: YESHISTORY: YESCONNECTION_TYPE: NULLTHREAD_OS_ID: 4625RESOURCE_GROUP: SYS_default

查看MySQL支持的字符集，一般使用的是utf8和utf8mb4

(root@localhost) [(none)]> show charset;
+----------+---------------------------------+---------------------+--------+
| Charset  | Description                     | Default collation   | Maxlen |
+----------+---------------------------------+---------------------+--------+
| armscii8 | ARMSCII-8 Armenian              | armscii8_general_ci |      1 |
| ascii    | US ASCII                        | ascii_general_ci    |      1 |
| big5     | Big5 Traditional Chinese        | big5_chinese_ci     |      2 |
| binary   | Binary pseudo charset           | binary              |      1 |
| cp1250   | Windows Central European        | cp1250_general_ci   |      1 |
| cp1251   | Windows Cyrillic                | cp1251_general_ci   |      1 |
| cp1256   | Windows Arabic                  | cp1256_general_ci   |      1 |
| cp1257   | Windows Baltic                  | cp1257_general_ci   |      1 |
| cp850    | DOS West European               | cp850_general_ci    |      1 |
| cp852    | DOS Central European            | cp852_general_ci    |      1 |
| cp866    | DOS Russian                     | cp866_general_ci    |      1 |
| cp932    | SJIS for Windows Japanese       | cp932_japanese_ci   |      2 |
| dec8     | DEC West European               | dec8_swedish_ci     |      1 |
| eucjpms  | UJIS for Windows Japanese       | eucjpms_japanese_ci |      3 |
| euckr    | EUC-KR Korean                   | euckr_korean_ci     |      2 |
| gb18030  | China National Standard GB18030 | gb18030_chinese_ci  |      4 |
| gb2312   | GB2312 Simplified Chinese       | gb2312_chinese_ci   |      2 |
| gbk      | GBK Simplified Chinese          | gbk_chinese_ci      |      2 |
| geostd8  | GEOSTD8 Georgian                | geostd8_general_ci  |      1 |
| greek    | ISO 8859-7 Greek                | greek_general_ci    |      1 |
| hebrew   | ISO 8859-8 Hebrew               | hebrew_general_ci   |      1 |
| hp8      | HP West European                | hp8_english_ci      |      1 |
| keybcs2  | DOS Kamenicky Czech-Slovak      | keybcs2_general_ci  |      1 |
| koi8r    | KOI8-R Relcom Russian           | koi8r_general_ci    |      1 |
| koi8u    | KOI8-U Ukrainian                | koi8u_general_ci    |      1 |
| latin1   | cp1252 West European            | latin1_swedish_ci   |      1 |
| latin2   | ISO 8859-2 Central European     | latin2_general_ci   |      1 |
| latin5   | ISO 8859-9 Turkish              | latin5_turkish_ci   |      1 |
| latin7   | ISO 8859-13 Baltic              | latin7_general_ci   |      1 |
| macce    | Mac Central European            | macce_general_ci    |      1 |
| macroman | Mac West European               | macroman_general_ci |      1 |
| sjis     | Shift-JIS Japanese              | sjis_japanese_ci    |      2 |
| swe7     | 7bit Swedish                    | swe7_swedish_ci     |      1 |
| tis620   | TIS620 Thai                     | tis620_thai_ci      |      1 |
| ucs2     | UCS-2 Unicode                   | ucs2_general_ci     |      2 |
| ujis     | EUC-JP Japanese                 | ujis_japanese_ci    |      3 |
| utf16    | UTF-16 Unicode                  | utf16_general_ci    |      4 |
| utf16le  | UTF-16LE Unicode                | utf16le_general_ci  |      4 |
| utf32    | UTF-32 Unicode                  | utf32_general_ci    |      4 |
| utf8     | UTF-8 Unicode                   | utf8_general_ci     |      3 |
| utf8mb4  | UTF-8 Unicode                   | utf8mb4_0900_ai_ci  |      4 |
+----------+---------------------------------+---------------------+--------+
41 rows in set (0.04 sec)

查询字符ASCII码

(root@localhost) [(none)]> select ascii('a');
+------------+
| ascii('a') |
+------------+
|         97 |
+------------+
1 row in set (0.00 sec)

查看字符集的排序规则

(root@localhost) [(none)]> show collation;
+----------------------------+----------+-----+---------+----------+---------+---------------+
| Collation                  | Charset  | Id  | Default | Compiled | Sortlen | Pad_attribute |
+----------------------------+----------+-----+---------+----------+---------+---------------+
| armscii8_bin               | armscii8 |  64 |         | Yes      |       1 | PAD SPACE     |
| armscii8_general_ci        | armscii8 |  32 | Yes     | Yes      |       1 | PAD SPACE     |
| ascii_bin                  | ascii    |  65 |         | Yes      |       1 | PAD SPACE     |
| ascii_general_ci           | ascii    |  11 | Yes     | Yes      |       1 | PAD SPACE     |
| big5_bin                   | big5     |  84 |         | Yes      |       1 | PAD SPACE     |
| big5_chinese_ci            | big5     |   1 | Yes     | Yes      |       1 | PAD SPACE     |
| binary                     | binary   |  63 | Yes     | Yes      |       1 | NO PAD        |
| cp1250_bin                 | cp1250   |  66 |         | Yes      |       1 | PAD SPACE     |
| cp1250_croatian_ci         | cp1250   |  44 |         | Yes      |       1 | PAD SPACE     |
| cp1250_czech_cs            | cp1250   |  34 |         | Yes      |       2 | PAD SPACE     |

查看所有的存储引擎

(root@localhost) [(none)]> show engines;
+--------------------+---------+----------------------------------------------------------------+--------------+------+------------+
| Engine             | Support | Comment                                                        | Transactions | XA   | Savepoints |
+--------------------+---------+----------------------------------------------------------------+--------------+------+------------+
| FEDERATED          | NO      | Federated MySQL storage engine                                 | NULL         | NULL | NULL       |
| MEMORY             | YES     | Hash based, stored in memory, useful for temporary tables      | NO           | NO   | NO         |
| InnoDB             | DEFAULT | Supports transactions, row-level locking, and foreign keys     | YES          | YES  | YES        |
| PERFORMANCE_SCHEMA | YES     | Performance Schema                                             | NO           | NO   | NO         |
| MyISAM             | YES     | MyISAM storage engine                                          | NO           | NO   | NO         |
| MRG_MYISAM         | YES     | Collection of identical MyISAM tables                          | NO           | NO   | NO         |
| BLACKHOLE          | YES     | /dev/null storage engine (anything you write to it disappears) | NO           | NO   | NO         |
| CSV                | YES     | CSV storage engine                                             | NO           | NO   | NO         |
| ARCHIVE            | YES     | Archive storage engine                                         | NO           | NO   | NO         |
+--------------------+---------+----------------------------------------------------------------+--------------+------+------------+

查看建库详细

(root@localhost) [(none)]> show create database testdb;
+----------+----------------------------------------------------------------------------------------------------+
| Database | Create Database                                                                                    |
+----------+----------------------------------------------------------------------------------------------------+
| testdb   | CREATE DATABASE `testdb` /*!40100 DEFAULT CHARACTER SET utf8 */ /*!80016 DEFAULT ENCRYPTION='N' */ |
+----------+----------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)