Linux——mysql运维篇-编程知识

回顾基本语句：

数据定义语言 ( DDL ) 。这类语言用于定义和修改数据库的结构，包括创建、删除和修改数据库、表、视图和索引等对象。主要的语句关键字包括 CREATE 、 DROP 、 ALTER 、 RENAME 、 TRUNCATE 等。

create database 数据库；
create table 表（列1 数据类型 [ 约束条件]，列2 数据类型【约束条件】……） add CONTRAINT 增加一些主键或者外键的约束
drop table/ drop database;
truncate 表；
rename 旧表名 TO 新表名；
alter 表 add 列 / drop 列 /
create view (虚表) / drop view
create user / drop user

数据操作语言 (DML ) 。用于添加、删除、更新和查询数据库中的记录。这些语句是关系型数据库的核心，用于操作表中的数据。主要的语句关键字包括 INSERT 、 DELETE 、 UPDATE 、 SELECT 等。

select 表的数据查询 from 表 WHERE 过滤条件 group by 列 order by ;
insert into 表（列1……）values (一行数据【和列是对应输入的】)，（第二行数据）……；
update 表 SET 列 = 值 where 过滤条件（定位修改的数据行）；
delete from 表 where 过滤条件；

数据控制语言 ( DCL ) 。用于定义和管理数据库、表、字段或用户的访问权限和安全级别。主要的语句关键字包括 GRANT 、 REVOKE 、 COMMIT 、 ROLLBACK 等。

GRANT // 数据库用户的授权对应权限的内容见 MySQL CRASH COURSE p257 表 28.1
revoke // 数据库用户权限的回收【撤销】
commit / rollback // 对于事务的提交和回滚【第26章】

数据查询语言 (DQL) 。这是专门用于从数据库中检索数据 / f

select cur();
select version();

联合查询等

join
UNION

一、安装

1. 源码编译安装

1. 获取源码

1. boost(包含这个组件的源码包

2. cmake ---> 生成 makefile

3. make

4. make install

5. 进行一些基础的优化

2. 二进制（软件包中包括已经编译完成的二进制程序以及需要的文件和配置文件

1. 直接获取安装需要的所有软件包的 bundle 包，然后进行安装【 mysql 安装】

2. 直接配置 mysql 官方的仓库

通过yum 仓库安装

1. 添加 yum 仓库

[root@bogon ~]# wget https://repo.mysql.com//mysql80-community- release-el8-9.noarch.rpm

--2024-04-27 20:31:45-- https://repo.mysql.com//mysql80-community

release-el8-9.noarch.rpm

Resolving repo.mysql.com (repo.mysql.com)... 23.210.109.97,

2a02:26f0:d8:980::1d68, 2a02:26f0:d8:98f::1d68

Connecting to repo.mysql.com (repo.mysql.com)|23.210.109.97|:443...

connected.

HTTP request sent, awaiting response... 200 OK

Length: 17792 (17K) [application/x-redhat-package-manager]

Saving to: ‘mysql80-community-release-el8-9.noarch.rpm’

mysql80-community-release-el8-9 100%

[=====================================================>] 17.38K -

-.-KB/s in 0.006s

2024-04-27 20:31:45 (3.02 MB/s) - ‘mysql80-community-release-el8-

9.noarch.rpm’ saved [17792/17792]

[root@bogon ~]# ls

aaa Desktop Downloads Music

original-ks.cfg Public Videos

anaconda-ks.cfg Documents keys mysql80-community-release

el8-9.noarch.rpm Pictures Templates

[root@bogon ~]# rpm -ivh mysql80-community-release-el8-9.noarch.rpm

[root@bogon ~]# ls /etc/yum.repos.d/

aa.repo bb.repo mysql-community-debuginfo.repo mysql

community.repo mysql-community-source.repo redhat.repo

[root@bogon ~]# yum -y remove mysql* mariadb*

[root@bogon ~]# yum module disable mysql -y

# 可选，如果已经在系统中进行了相关数据的安装（ mariadb 以及 mysql ）

# rpm -qa | egrep 'mysql|mariadb'

# 如果有提示任何包的安装信息，需要先卸载对应的包，然后再禁用下面的模块

# yum module -y disable mysql # 禁用原本启用的 mysql 模块，后续安

装时，可以使用第一步所设置的仓库进行安装

2. 安装 server 包

[root@bogon ~]# yum install mysql-community-server

3. 启动服务

完成数据的初始化

创建基本的数据库和表

完成 mysql 超级用户 root@localhost 的创建以及密码的生成（限制 root 用户只能从

mysql 运行的节点登录）

[root@mysql8 ~]# systemctl start mysqld

# 抓取用户密码

[root@mysql8 ~]# grep password /var/log/mysqld.log

2024-04-28T00:27:27.590106Z 6 [Note] [MY-010454] [Server] A

temporary password is generated for root@localhost: f%EqxVUy9d5u

# 修改密码

[root@mysql8 ~]# mysql -u root -p'f%EqxVUy9d5u' -h localhost

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: 8.0.36

Copyright (c) 2000, 2024, 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> alter user root@localhost identified by 'Redhat12~';

Query OK, 0 rows affected (0.01 sec)

3. 补充 MySQL 用户管理

默认情况下，只要 root@localhost ，也就是说只能通过 127.0.0.1 建立连接并连接到数据库，

一旦在连接数据库时，不是使用 127.0.0.1 就会拒绝请求

[root@mysql8 ~]# mysql -u root -p'Redhat12~' -h localhost

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 15

Server version: 8.0.36 MySQL Community Server - GPL

Copyright (c) 2000, 2024, 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.

[root@mysql8 ~]# mysql -u root -p'Redhat12~' -h 192.168.110.50

mysql: [Warning] Using a password on the command line interface can

be insecure.

ERROR 1130 (HY000): Host '192.168.110.50' is not allowed to connect

to this MySQL server

-h 192.168.110.50 // 指定数据库服务器的 IP 地址

需要先创建对应客户端 IP 地址的用户，才可以访问

mysql-1: 192.168.110.50

bogon: 192.168.110.131

# 从 localhost 登录，授权可以从 192.168.110.50 登录

[root@mysql8 ~]# mysql -u root -p'Redhat12~' -h localhost

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 15

Server version: 8.0.36 MySQL Community Server - GPL

Copyright (c) 2000, 2024, 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.

mysql> create user root@'192.168.110.50' identified by 'Redhat12~';

Query OK, 0 rows affected (0.00 sec)

mysql> flush privileges;

Query OK, 0 rows affected (0.00 sec)

mysql> flush privileges;

Query OK, 0 rows affected (0.00 sec)

mysql> exit

Bye

再次尝试

[root@mysql8 ~]# mysql -u root -p'Redhat12~' -h 192.168.110.50

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 13

Server version: 8.0.36 MySQL Community Server - GPL

Copyright (c) 2000, 2024, 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> use mysql; // 其实是一个全新为授权任何库或者表，或者语句，因此除了登

录

// 什么也不能干

// 通过 select * from mysql.user 发现新建的名为 root

// 主机名为 192.168.110.50 的用户任何权限都没有

ERROR 1044 (42000): Access denied for user 'root'@'192.168.110.50' to

database 'mysql'

mysql> exit

Bye

因为只授权了可以从 192.168.110.50 登录，在 192.168.110.131 上是无法登录的

[root@bogon ~]# mysql -u root -p'Redhat12~' -h 192.168.110.50

mysql: [Warning] Using a password on the command line interface can beinsecure.

ERROR 1130 (HY000): Host '192.168.110.131' is not allowed to connect to this

MySQL server

# 引申：如果需要从 192.168.110.131 登录数据库就需要再授权一个用户可以从

192.168.110.131 登录

lamp

grant all webapp.* to appuser@'192.168.110.%' identified by 'mima';

4. 升级降级

1. 确定安装方式

2. 数据迁移

二、配置

调整数据库管理系统的密码策略

MySQL :: MySQL 8.0 Reference Manual :: 8.4.3.2 Password Validation Options and Variables

https://dev.mysql.com/doc/refman/8.0/en/validate-password-options-variables.html

数据目录

一般写在配置文件中 datadir

auto.cnf ／／持久生效的所有变量以及对应的值

bin log .index binlog.000002 binlog.000003 bin log .000001 ／／日志

client-key.pem server-key.pem

ca-key.pem ca.pem private_key.pem cert.pem server-cert.pem

public_key.pem ／／加密通信需要使用的秘钥和证书

mysql performance_schema sys ／／这三个是目录，所有的Ｍｙｓｑｌ下的库都会创建属于自己的目录来保存库中表的数据

／／使用ｉｎｎｏｄｂ存储引擎的表文件会被存储成一个文件

／／使用ｍｙｉｓａｍ存储引擎的表文件，会存储成多个文件

ibdata1 '#ib_16384_0.dblwr' ibtmp1 mysql.ibd '#ib_16384_1.dblwr'

'#innodb_redo' undo_001

client- ib_buffer_pool '#innodb_temp' undo_002 ／／ｉｎｎｏｄｂ存储引擎运行期间产生的额外数据（索引、事务等）临时性的运行文件

mysql 对于所有用户和相关的配置都保存在具体的数据表中，下面引入一些简单的关于用户授权的表格：

mysql.user: 用户账号信息，以及全局范围的授权数据【所有库所有表都可以进行查询操作，则显示此用户具有查询权限】
global_grants: 全局授权表，表数据本身不断发生变换，根据实时授权的信息变化
db: 对于库级别操作的授权
tables_priv: 显示表级别的授权
columns_priv: 对于数据列的授权
procs_priv: 对于存储过程的授权【create procedures】
proxies_proc: 代理用户权限
default_role: 默认的角色，角色可以理解为已经定义好的权限的合集，直接可以授权给指定用户避免一个一个授权的尴尬
password_history: 密码变更的历史信息

系统运行维护相关表：

general_log：记录查询记录
slow_log：慢查询日志
time_zone: 时区信息和时区差距

主从复制系统表格

gtid_executed: GTID 组数据的保存，以gtid写入数据，保证数据一致性
ndb_binlog_index: 二进制日志的索引
slave* : 从节点的状态

配置文件

熟悉 mysql 配置文件结构

主配置文件：／ｅｔｃ／ｍｙ．ｃｎｆ

额外的附加配置文件路径：／ｅｔｃ／ｍｙ．ｃｎｆ．ｄ／＊．ｃｎｆ

数据库的配置是通过一些环境变量控制，可以在运行状态下，直接修改环境变量的值，生效配置,但是因为服务在重启时，会加载记录在配置文件中的变量的值，因为会恢复成默认值，如果需要配置持久化生效，需要直接写入配置文件。

数据库的配置文件，包括多个不同的配置块 ([] 来表示不同的配置块 ) ， [mysqld] 对于服务端的守护进程去进行配置。

MySQL 日志

二进制启用后，后导致数据库运行效率降低。可以通过二进制日志实现数据备份和数据同步的作。

二进制日志不能很好的应对突然发生的服务中断（停止），只有已经执行完毕的语句和事务才会录，张中断时，正在进行的数据变化不会被记录到二进制日志。

-- log - bin 启用二进制日志。

-- skip - log - bin -- disable - log - bin 禁用二进制日志。

二进制日志的更新：（更新编号）

1 、每一次数据库守护进程重新启动

2 、执行 flush 二进制日志

3 、设定了二进制日志的最大大小

三、备份与还原

数据库的数据备份就是为了进行数据还原。保证数据完整性和一致性。备份：

1. 物理备份

1. 物理备份一般是针对数据库的数据目录进行的备份（可以直接使用文件操作命令实现）

2. 物理备份速度取决于磁盘 IO 速度，效率很高

3. 输出的备份日志更具有可读性

4. 物理备份可能包含不需要的日志文件以及配置

5. 对于数据备份的颗粒度，需要取决于不同的存储引擎

6. 物理备份的时候，一般需要设置专门的读写锁，或者停止 mysql 服务，来避免在备份过程中出现任何新数据的写入，避免备份遗漏数据。

2. 逻辑备份（mysqldump）

1. 通过向数据库服务查询相关数据来产生数据备份

2. 逻辑备份的效率远低于物理备份

3. 逻辑备份的数据量可能远大于物理备份，兼容性相对较低（逻辑备份不能在版本差异较大的数据库之间实现数据的恢复）

4. 逻辑备份完全规避日志和配置文件

5. 逻辑备份期间，数据库需要处于运行状态

6. 逻辑备份使用 mysqldump SELELCT OUTFILE 文件路径

7. 进行数据恢复，通过 mysql 或者 LOAD DATA mysqlimport 实现

在线备份和离线备份（热备份和冷备份）

在线： mysql 服务处于运行状态下，进行的备份叫做在线备份（热备份），反之冷备份和离线备份

一般对于一直处于业务处理场景下的数据库进行热备份对于业务处理量较小或者是指主业务库数据副本节点进行冷备份。

本地备份和远程备份

在数据库的节点上进行的备份，是本地备份。从远程节点进行备份是远程备份。

cp / tar // 本地备份（物理备份）

scp / sftp / rsync // 可以针对数据库进行远程备份程序（物理备份）

快照备份

数据库本身并不提供这个功能。逻辑卷和 xfs 、 Veritas 、 ZFS 文件系统都提供快照的功能

全量备份增量备份

每一次备份都是对于数据库全部文件的备份，称之为全量备份。

每一次备份会和上一次备份比较，仅备份发生变化的部分，称之为增量备份。

数据表的数据完整性

1. innodb 数据库一般不存在数据碎坏，丢失的问题

2. MyISAM 数据表比较可能因为缺少表结构文件、表索引、表数据文件等导致数据损坏，通过MyISAM 检查工具检查表数据的完整性

mysqldump 备份数据库实验

使用场景：

1. 为了防止数据丢失，对整个数据库进行全量备份

2. 在进行主从架构搭建的时候，向从库导入数据的一种手段

3. 作为实验数据的源数据

1. 为整个数据库制作一个副本，而不需要直接修改源数据库的数据

2. 为了检验数据库升级之后的数据迁移能够顺利进行

逻辑备份：

1. 备份 mysqldump

2. 恢复数据

1. 系统 shell mysql -u root -p [db] < dump.sql

2. MYSQL shell source 备份文件路径

[root@mysql-1 ~]# mysql -u root -predhat
mysql: [Warning] Using a password on the command line interface can beinsecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 8
Server version: 8.0.36 MySQL Community Server - GPL
Copyright (c) 2000, 2024, 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 inputstatement.
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| sys |
+--------------------+
4 rows in set (0.01 sec)
mysql> create database test;
Query OK, 1 row affected (0.00 sec)
mysql> use test;
Database changed
mysql> create table a (id int, name char(8));
Query OK, 0 rows affected (0.02 sec)
mysql> insert into a values(1, 'aaa'), (2, 'bbb'), (3, 'ccc');
Query OK, 3 rows affected (0.08 sec)
Records: 3 Duplicates: 0 Warnings: 0
mysql> select * from a;
+------+------+
| id | name |
+------+------+
| 1 | aaa |
| 2 | bbb |
| 3 | ccc |
+------+------+
3 rows in set (0.00 sec)
mysql> exit
Bye
[root@mysql-1 ~]# mysqldump -u root -predhat --databases test > backup.sql
// 有创建库的语句，所以只能恢复到原本的库中
mysqldump: [Warning] Using a password on the command line interface can be
insecure.
[root@mysql-1 ~]# cat backup.sql
-- MySQL dump 10.13 Distrib 8.0.36, for Linux (x86_64)
--
-- Host: localhost Database: test
-- ------------------------------------------------------
-- Server version 8.0.36
/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;
/*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */;
/*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */;
/*!50503 SET NAMES utf8mb4 */;
/*!40103 SET @OLD_TIME_ZONE=@@TIME_ZONE */;
/*!40103 SET TIME_ZONE='+00:00' */;
/*!40014 SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0 */;
/*!40014 SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS,
FOREIGN_KEY_CHECKS=0 */;
/*!40101 SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='NO_AUTO_VALUE_ON_ZERO'
*/;
/*!40111 SET @OLD_SQL_NOTES=@@SQL_NOTES, SQL_NOTES=0 */;
--
-- Current Database: `test`
--
CREATE DATABASE /*!32312 IF NOT EXISTS*/ `test` /*!40100 DEFAULT CHARACTER
SET utf8mb4 COLLATE utf8mb4_0900_ai_ci */ /*!80016 DEFAULT ENCRYPTION='N'
*/;
USE `test`;
--
-- Table structure for table `a`
--
DROP TABLE IF EXISTS `a`;
/*!40101 SET @saved_cs_client = @@character_set_client */;
/*!50503 SET character_set_client = utf8mb4 */;
CREATE TABLE `a` (
`id` int DEFAULT NULL,
`name` char(8) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;
/*!40101 SET character_set_client = @saved_cs_client */;
--
-- Dumping data for table `a`
--
LOCK TABLES `a` WRITE;
/*!40000 ALTER TABLE `a` DISABLE KEYS */;
INSERT INTO `a` VALUES (1,'aaa'),(2,'bbb'),(3,'ccc');
/*!40000 ALTER TABLE `a` ENABLE KEYS */;
UNLOCK TABLES;
/*!40103 SET TIME_ZONE=@OLD_TIME_ZONE */;
/*!40101 SET SQL_MODE=@OLD_SQL_MODE */;
/*!40014 SET FOREIGN_KEY_CHECKS=@OLD_FOREIGN_KEY_CHECKS */;
/*!40014 SET UNIQUE_CHECKS=@OLD_UNIQUE_CHECKS */;
/*!40101 SET CHARACTER_SET_CLIENT=@OLD_CHARACTER_SET_CLIENT */;
/*!40101 SET CHARACTER_SET_RESULTS=@OLD_CHARACTER_SET_RESULTS */;
/*!40101 SET COLLATION_CONNECTION=@OLD_COLLATION_CONNECTION */;
/*!40111 SET SQL_NOTES=@OLD_SQL_NOTES */;
-- Dump completed on 2024-04-28 23:47:16
[root@mysql-1 ~]# mysqldump -u root -predhat test > backup01.sql
mysqldump: [Warning] Using a password on the command line interface can be
insecure.
// 没有创建库的语句，所以可能恢复的任意指定的数据库中
[root@mysql-1 ~]# cat backup01.sql
-- MySQL dump 10.13 Distrib 8.0.36, for Linux (x86_64)
--
-- Host: localhost Database: test
-- ------------------------------------------------------
-- Server version 8.0.36
/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;
/*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */;
/*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */;
/*!50503 SET NAMES utf8mb4 */;
/*!40103 SET @OLD_TIME_ZONE=@@TIME_ZONE */;
/*!40103 SET TIME_ZONE='+00:00' */;
/*!40014 SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0 */;
/*!40014 SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS,
FOREIGN_KEY_CHECKS=0 */;
/*!40101 SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='NO_AUTO_VALUE_ON_ZERO'
*/;
/*!40111 SET @OLD_SQL_NOTES=@@SQL_NOTES, SQL_NOTES=0 */;
--
-- Table structure for table `a`
--
DROP TABLE IF EXISTS `a`;
/*!40101 SET @saved_cs_client = @@character_set_client */;
/*!50503 SET character_set_client = utf8mb4 */;
CREATE TABLE `a` (
`id` int DEFAULT NULL,
`name` char(8) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;
/*!40101 SET character_set_client = @saved_cs_client */;
--
-- Dumping data for table `a`
--
LOCK TABLES `a` WRITE;
/*!40000 ALTER TABLE `a` DISABLE KEYS */;
INSERT INTO `a` VALUES (1,'aaa'),(2,'bbb'),(3,'ccc');
/*!40000 ALTER TABLE `a` ENABLE KEYS */;
UNLOCK TABLES;
/*!40103 SET TIME_ZONE=@OLD_TIME_ZONE */;
/*!40101 SET SQL_MODE=@OLD_SQL_MODE */;
/*!40014 SET FOREIGN_KEY_CHECKS=@OLD_FOREIGN_KEY_CHECKS */;
/*!40014 SET UNIQUE_CHECKS=@OLD_UNIQUE_CHECKS */;
/*!40101 SET CHARACTER_SET_CLIENT=@OLD_CHARACTER_SET_CLIENT */;
/*!40101 SET CHARACTER_SET_RESULTS=@OLD_CHARACTER_SET_RESULTS */;
/*!40101 SET COLLATION_CONNECTION=@OLD_COLLATION_CONNECTION */;
/*!40111 SET SQL_NOTES=@OLD_SQL_NOTES */;
-- Dump completed on 2024-04-28 23:50:33
[root@mysql-1 ~]# mysql -u root -predhat
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 11
Server version: 8.0.36 MySQL Community Server - GPL
Copyright (c) 2000, 2024, 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> drop database test;
Query OK, 1 row affected (0.01 sec)
mysql> exit
Bye
[root@mysql-1 ~]# mysql -u root -predhat < backup.sql
mysql: [Warning] Using a password on the command line interface can be
insecure.
[root@mysql-1 ~]# mysql -u root -predhat
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 14
Server version: 8.0.36 MySQL Community Server - GPL
Copyright (c) 2000, 2024, 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;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| sys |
| test |
+--------------------+
5 rows in set (0.00 sec)
mysql> select * from test.a;
+------+------+
| id | name |
+------+------+
| 1 | aaa |
| 2 | bbb |
| 3 | ccc |
+------+------+
3 rows in set (0.00 sec)
mysql> exit
Bye
# 另一种恢复数据的方法
[root@mysql-1 ~]# mysql -u root -predhat
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 15
Server version: 8.0.36 MySQL Community Server - GPL
Copyright (c) 2000, 2024, 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> drop database test;
Query OK, 1 row affected (0.01 sec)
mysql> source /root/backup.sql
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.01 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 1 row affected (0.00 sec)
Database changed
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.02 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 3 rows affected (0.01 sec)
Records: 3 Duplicates: 0 Warnings: 0
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
mysql> select * from test.a;
+------+------+
| id | name |
+------+------+
| 1 | aaa |
| 2 | bbb |
| 3 | ccc |
+------+------+
3 rows in set (0.00 sec)
mysql> drop database test;
Query OK, 1 row affected (0.01 sec)
mysql> source /root/backup01.sql //这个备份中没有创建库和切换库的语句，所以恢复
数据失败，需要先切换到库中（这里可以尝试恢复到其他库中）
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
ERROR 1046 (3D000): No database selected
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
ERROR 1046 (3D000): No database selected
Query OK, 0 rows affected (0.00 sec)
ERROR 1046 (3D000): No database selected
ERROR 1046 (3D000): No database selected
ERROR 1046 (3D000): No database selected
ERROR 1046 (3D000): No database selected
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
mysql> select * from test.a;
ERROR 1049 (42000): Unknown database 'test'
mysql> create database test;
Query OK, 1 row affected (0.01 sec)
mysql> use test;
Database changed
mysql> source /root/backup01.sql
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.01 sec)
Query OK, 0 rows affected (0.04 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.01 sec)
Query OK, 3 rows affected (0.00 sec)
Records: 3 Duplicates: 0 Warnings: 0
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
mysql> select * from a;
+------+------+
| id | name |
+------+------+
| 1 | aaa |
| 2 | bbb |
| 3 | ccc |
+------+------+
3 rows in set (0.00 sec)
mysql> drop table a;
Query OK, 0 rows affected (0.01 sec)
mysql> exit
Bye
[root@mysql-1 ~]# mysql -u root -predhat test < backup01.sql
mysql: [Warning] Using a password on the command line interface can be
insecure.
[root@mysql-1 ~]# mysql -u root -predhat
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 17
Server version: 8.0.36 MySQL Community Server - GPL
Copyright (c) 2000, 2024, 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> select * from test.a;
+------+------+
| id | name |
+------+------+
| 1 | aaa |
| 2 | bbb |
| 3 | ccc |
+------+------+
3 rows in set (0.00 sec)
mysql>
mysql> exit
Bye
# 使用--tab 在备份时，分离表结构和表数据，在恢复时，也可以分开恢复
[root@mysql-1 ~]# mysqldump -u root -p --tab=/var/lib/mysql-files test
Enter password:
[root@mysql-1 ~]# ls /var/lib/mysql-files/
a.sql a.txt
# 恢复表
[root@mysql-1 ~]# mysql -u root -predhat test < /var/lib/mysql-files/a.sql
mysql: [Warning] Using a password on the command line interface can be
insecure.
# 需要test库是存在的
# 恢复数据
[root@mysql-1 ~]# mysqlimport -u root -predhat test /var/lib/mysqlfiles/a.txt
mysqlimport: [Warning] Using a password on the command line interface can
be insecure.
test.a: Records: 3 Deleted: 0 Skipped: 0 Warnings: 0

物理备份：

1. 备份：使用文件备份的命令直接创建压缩包备份或者 cp 等命令创建数据文件副本

2. 恢复：把备份的文件还原到原本的数据目录中即可，文件的权限和 selinux 标签是需要注意

[root@mysql-1 ~]# mkdir /db_backup; cp -r /var/lib/mysql/test/ /db_backup/
[root@mysql-1 ~]# ls /var/lib/mysql/test/
a.ibd
[root@mysql-1 ~]# ls /db_backup/test/
a.ibd
[root@mysql-1 ~]# rm -rf /var/lib/mysql/test/
[root@mysql-1 ~]# mysql -u root -predhat
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 27
Server version: 8.0.36 MySQL Community Server - GPL
Copyright (c) 2000, 2024, 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;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| sys |
| test |
+--------------------+
5 rows in set (0.00 sec)
mysql> use test;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed
mysql> show tables;
+----------------+
| Tables_in_test |
+----------------+
| a |
+----------------+
1 row in set (0.00 sec)
mysql> select * from a;
+------+------+
| id | name |
+------+------+
| 1 | aaa |
| 2 | bbb |
| 3 | ccc |
+------+------+
3 rows in set (0.01 sec)
mysql> exit
Bye
[root@mysql-1 ~]# systemctl restart mysqld
[root@mysql-1 ~]# ls /var/lib/mysql/test
ls: cannot access '/var/lib/mysql/test': No such file or directory
[root@mysql-1 ~]# mysql -u root -predhat
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 8
Server version: 8.0.36 MySQL Community Server - GPL
Copyright (c) 2000, 2024, 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;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| sys |
| test |
+--------------------+
5 rows in set (0.01 sec)
mysql> use test;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed
mysql> select * from a;
ERROR 1812 (HY000): Tablespace is missing for table `test`.`a`.
mysql> exit
Bye
[root@mysql-1 ~]# systemctl stop mysqld
[root@mysql-1 ~]# mv /db_backup/test/ /var/lib/mysql/
[root@mysql-1 ~]# ls /var/lib/mysql/test
a.ibd
[root@mysql-1 ~]# restorecon -Rvv /var/lib/mysql/test/
Relabeled /var/lib/mysql/test from unconfined_u:object_r:default_t:s0 to
unconfined_u:object_r:mysqld_db_t:s0
Relabeled /var/lib/mysql/test/a.ibd from
unconfined_u:object_r:default_t:s0 to unconfined_u:object_r:mysqld_db_t:s0
[root@mysql-1 ~]# chown -R mysql.mysql /var/lib/mysql/test/
[root@mysql-1 ~]# systemctl restart mysqld
[root@mysql-1 ~]# mysql -u root -predhat
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 8
Server version: 8.0.36 MySQL Community Server - GPL
Copyright (c) 2000, 2024, 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> select * from test.a;
+------+------+
| id | name |
+------+------+
| 1 | aaa |
| 2 | bbb |
| 3 | ccc |
+------+------+
3 rows in set (0.01 sec)
mysql> exit
Bye
# 使用tar 不需要关注文件的权限和标签
[root@mysql-1 ~]# cd /var/lib/mysql
[root@mysql-1 mysql]# tar -czf testdb.tar.gz test/
[root@mysql-1 mysql]# tar -tf testdb.tar.gz
test/
test/a.ibd
[root@mysql-1 mysql]# systemctl stop mysql
Failed to stop mysql.service: Unit mysql.service not loaded.
[root@mysql-1 mysql]# systemctl stop mysqld
[root@mysql-1 mysql]# pwd
/var/lib/mysql
[root@mysql-1 mysql]# rm -rf testq
[root@mysql-1 mysql]# rm -rf test
[root@mysql-1 mysql]# tar -xzf testdb.tar.gz .
tar: .: Not found in archive
tar: Exiting with failure status due to previous errors
[root@mysql-1 mysql]#
[root@mysql-1 mysql]# tar -xzf testdb.tar.gz -C .
[root@mysql-1 mysql]# ls test
a.ibd
[root@mysql-1 mysql]# ll -d test
drwxr-x---. 2 mysql mysql 19 Apr 29 00:09 test
[root@mysql-1 mysql]# ll -dZ test
drwxr-x---. 2 mysql mysql unconfined_u:object_r:mysqld_db_t:s0 19 Apr 29
00:09 test
[root@mysql-1 mysql]# rm -rf test
[root@mysql-1 mysql]# ll test
ls: cannot access 'test': No such file or directory
[root@mysql-1 mysql]# !tar
tar -xzf testdb.tar.gz -C .
[root@mysql-1 mysql]# ll -dZ test
drwxr-x---. 2 mysql mysql unconfined_u:object_r:mysqld_db_t:s0 19 Apr 29
00:09 test
[root@mysql-1 mysql]# ll -Z test
total 112
-rw-r-----. 1 mysql mysql unconfined_u:object_r:mysqld_db_t:s0 114688 Apr
29 00:09 a.ibd
[root@mysql-1 mysql]# systemctl start mysqld
[root@mysql-1 mysql]# mysql -u root -predhat
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 8
Server version: 8.0.36 MySQL Community Server - GPL
Copyright (c) 2000, 2024, 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> select * from test.a;
+------+------+
| id | name |
+------+------+
| 1 | aaa |
| 2 | bbb |
| 3 | ccc |
+------+------+
3 rows in set (0.00 sec)
mysql> exit
Bye