权限管理及数据备份与恢复
**作者：行癫（盗版必究）**
------
## 一：权限管理
#### 1.权限级别
Global level：系统级，所有库，所有表的权限
Database level：某个数据库中的所有表的权限
Table level：库中的某个表的权限
Column level：表中的某个字段的权限
procs level：某个存储过程的权限
proxies level：代理服务器的权限
#### 2.查看权限记录表
因为超级管理员默认已经设置；所以直接查询权限即可
##### Global level
```
mysql> select * from mysql.user\G
*************************** 1. row ***************************
Host: localhost
User: root
Select_priv: Y
Insert_priv: Y
Update_priv: Y
Delete_priv: Y
Create_priv: Y
Drop_priv: Y
Reload_priv: Y
Shutdown_priv: Y
Process_priv: Y
File_priv: Y
Grant_priv: Y
References_priv: Y
Index_priv: Y
Alter_priv: Y
Show_db_priv: Y
Super_priv: Y
Create_tmp_table_priv: Y
Lock_tables_priv: Y
Execute_priv: Y
Repl_slave_priv: Y
Repl_client_priv: Y
Create_view_priv: Y
Show_view_priv: Y
Create_routine_priv: Y
Alter_routine_priv: Y
Create_user_priv: Y
Event_priv: Y
Trigger_priv: Y
Create_tablespace_priv: Y
ssl_type:
ssl_cipher:
x509_issuer:
x509_subject:
max_questions: 0
max_updates: 0
max_connections: 0
max_user_connections: 0
plugin: mysql_native_password
authentication_string: *B1DD4ADE47888D9AEC4D705C85230F1B52D2A817
password_expired: N
password_last_changed: 2022-09-25 14:44:38
password_lifetime: NULL
account_locked: N
```
字段介绍：
```shell
用户字段：root
权限字段：Select_priv
安全字段：*B1DD4ADE47888D9AEC4D705C85230F1B52D2A817
Select_priv：查询权限
Insert_priv：插入权限
Update_priv：更新权限
Delete_priv：删除权限
......
```
##### Database level
```shell
mysql> select * from mysql.db\G;
*************************** 1. row ***************************
Host: localhost
Db: performance_schema
User: mysql.session
Select_priv: Y
Insert_priv: N
Update_priv: N
Delete_priv: N
Create_priv: N
Drop_priv: N
Grant_priv: N
References_priv: N
Index_priv: N
Alter_priv: N
Create_tmp_table_priv: N
Lock_tables_priv: N
Create_view_priv: N
Show_view_priv: N
Create_routine_priv: N
Alter_routine_priv: N
Execute_priv: N
Event_priv: N
Trigger_priv: N
```
测试库权限：
```shell
mysql> create database t1;
Query OK, 1 row affected (0.00 sec)
mysql> grant all on t1.* to 't1'@'localhost' identified by 'QianFeng@123';
Query OK, 0 rows affected, 1 warning (0.00 sec)
```
查看：
```
mysql> select * from mysql.db\G
*************************** 3. row ***************************
Host: localhost
Db: t1
User: t1
Select_priv: Y
Insert_priv: Y
Update_priv: Y
Delete_priv: Y
Create_priv: Y
Drop_priv: Y
Grant_priv: N
References_priv: Y
Index_priv: Y
Alter_priv: Y
Create_tmp_table_priv: Y
Lock_tables_priv: Y
Create_view_priv: Y
Show_view_priv: Y
Create_routine_priv: Y
Alter_routine_priv: Y
Execute_priv: Y
Event_priv: Y
Trigger_priv: Y
3 rows in set (0.00 sec)
```
验证：
```shell
[root@xingdian ~]# mysql -u t1 -pQianFeng@123
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 4
Server version: 5.7.39-log MySQL Community Server (GPL)
Copyright (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;
+--------------------+
| Database |
+--------------------+
| information_schema |
| t1 |
+--------------------+
2 rows in set (0.00 sec)
```
##### Table level
```shell
mysql> select * from mysql.tables_priv\G;
*************************** 1. row ***************************
Host: localhost
Db: mysql
User: mysql.session
Table_name: user
Grantor: boot@connecting host
Timestamp: 0000-00-00 00:00:00
Table_priv: Select
Column_priv:
*************************** 2. row ***************************
Host: localhost
Db: sys
User: mysql.sys
Table_name: sys_config
Grantor: root@localhost
Timestamp: 2022-09-25 14:40:58
Table_priv: Select
Column_priv:
2 rows in set (0.00 sec)
```
创建库表验证：
```shell
mysql> create database t2;
Query OK, 1 row affected (0.00 sec)
mysql> use t2;
Database changed
mysql> create table u1(id int);
Query OK, 0 rows affected (0.01 sec)
mysql> insert into u1 values (1);
Query OK, 1 row affected (0.01 sec)
mysql> grant all on t2.u1 to 't2'@'localhost' identified by 'QianFeng@123';
Query OK, 0 rows affected, 1 warning (0.00 sec)
mysql> create table u2(id int);
Query OK, 0 rows affected (0.01 sec)
mysql> show tables;
+--------------+
| Tables_in_t2 |
+--------------+
| u1 |
| u2 |
+--------------+
2 rows in set (0.00 sec)
```
权限查看：
```shell
mysql> select * from mysql.tables_priv\G;
*************************** 3. row ***************************
Host: localhost
Db: t2
User: t2
Table_name: u1
Grantor: root@localhost
Timestamp: 0000-00-00 00:00:00
Table_priv: Select,Insert,Update,Delete,Create,Drop,References,Index,Alter,Create View,Show view,Trigger
Column_priv:
3 rows in set (0.00 sec)
```
验证：（登录t2账户，看到u1表，看不到u2代表权限成功）
```shell
[root@xingdian ~]# mysql -u t2 -pQianFeng@123
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 6
Server version: 5.7.39-log MySQL Community Server (GPL)
Copyright (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;
+--------------------+
| Database |
+--------------------+
| information_schema |
| t2 |
+--------------------+
2 rows in set (0.00 sec)
mysql> use t2;
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_t2 |
+--------------+
| u1 |
+--------------+
1 row in set (0.00 sec)
```
##### Column level
```shell
[root@xingdian ~]# mysql -uroot -pQianFeng@123
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 7
Server version: 5.7.39-log MySQL Community Server (GPL)
Copyright (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> select * from mysql.columns_priv\G;
Empty set (0.00 sec)
mysql> insert into mysql.columns_priv(host,db,user,table_name,column_name,column_priv) values('%','t2','t2','u1','id','select');
Query OK, 1 row affected (0.00 sec)
mysql> select * from mysql.columns_priv\G;
*************************** 1. row ***************************
Host: %
Db: t2
User: t2
Table_name: u1
Column_name: id
Timestamp: 2022-09-25 15:34:05
Column_priv: Select
1 row in set (0.00 sec)
```
注意：
前提是有库，有表，有权限
## 二：用户管理
#### 1.登录和退出
```shell
[root@xingdian ~]# mysql -h 192.168.18.160 -P 30042 -u root -pmysql -e "show databases;"
[root@xingdian ~]# mysql -h 192.168.18.160 -P 30042 -u root -pmysql mysql -e "show tables;"
-h 指定主机名 【默认为localhost】
-P MySQL服务器端口 【默认3306】
-u 指定用户名 【默认root】
-p 指定登录密码 【默认为空密码】
此处mysql为指定登录的数据库
-e 接SQL语句 (在脚本中使用)
```
#### 2.创建用户
方式一：
```shell
mysql> create user xingdian;
ERROR 1819 (HY000): Your password does not satisfy the current policy requirements
注意：
该报错是因为密码强度问题，取消密码强度即可创建用户
mysql> create user xingdian@'%' identified by 'QianFeng@123';
Query OK, 0 rows affected (0.00 sec)
```
方式二：
```shell
mysql> grant all on *.* to 'diange'@'localhost' identified by 'QianFeng@123';
Query OK, 0 rows affected, 1 warning (0.00 sec)
```
注意：
该方式采用授权的方式
ALL 所有权限 select 单独某一个权限（多个权限用逗号隔开）
```shell
mysql> grant select on *.* to 'dianye'@'localhost' identified by 'QianFeng@123';
Query OK, 0 rows affected, 1 warning (0.00 sec)
```
```shell
*.* 所有的库所有的表 也可以单独某一个库某一个表
```
```shell
xingdian@localhost 用户有则授权无则创建 localhost % 10.19.40.% 10.19.40.11
```
#### 3.删除用户
方式一：
```shell
MySQL [(none)]> Drop user xingdian@'%';
Query OK, 0 rows affected (0.00 sec)
```
方法二：
```shell
MySQL [(none)]> delete from mysql.user where user='diandian' AND Host='%';
Query OK, 1 row affected (0.00 sec)
```
#### 4.修改密码
方式一：
```shell
[root@xingdian ~]# mysqladmin -uroot -p'123' password 'new_password' //123为旧密码
```
方式二：
```shell
MySQL [(none)]> update mysql.user set authentication_string=password(123456) where user='diange' And Host='%';
```
注意：
刷新授权表后生效：flush privileges
自己设置自己密码：
```shell
MySQL [(none)]> set password='123';
Query OK, 0 rows affected (0.00 sec)
```
root用户修改其他用户密码：
方法一：
```shell
mysql> SET PASSWORD FOR user3@'localhost'='new_password';
```
方法二：
```shell
UPDATE mysql.user SET authentication_string=password('new_password') WHERE user='user3' AND host='localhost';
```
#### 5.查看密码策略
```shell
mysql> SHOW VARIABLES LIKE 'validate_password%';
+--------------------------------------+--------+
| Variable_name | Value |
+--------------------------------------+--------+
| validate_password_check_user_name | OFF |
| validate_password_dictionary_file | |
| validate_password_length | 8 |
| validate_password_mixed_case_count | 1 |
| validate_password_number_count | 1 |
| validate_password_policy | MEDIUM |
| validate_password_special_char_count | 1 |
+--------------------------------------+--------+
7 rows in set (0.00 sec)
```
参数解释：
validate_password_dictionary_file 指定密码验证的文件路径
validate_password_length 密码最小长度
validate_password_mixed_case_count 密码至少要包含的小写字母个数和大写字母个数
validate_password_number_count 密码至少要包含的数字个数
validate_password_policy 密码强度检查等级，对应等级为：0/LOW、1/MEDIUM、2/STRONG,默认为1
0/LOW：只检查长度
1/MEDIUM：检查长度、数字、大小写、特殊字符
2/STRONG：检查长度、数字、大小写、特殊字符字典文件
validate_password_special_char_count密码至少要包含的特殊字符数
修改密码策略：
```shell
mysql> SHOW VARIABLES LIKE 'validate_password%';
+--------------------------------------+--------+
| Variable_name | Value |
+--------------------------------------+--------+
| validate_password_check_user_name | OFF |
| validate_password_dictionary_file | |
| validate_password_length | 8 |
| validate_password_mixed_case_count | 1 |
| validate_password_number_count | 1 |
| validate_password_policy | MEDIUM |
| validate_password_special_char_count | 1 |
+--------------------------------------+--------+
7 rows in set (0.00 sec)
mysql> set global validate_password_length=4;
Query OK, 0 rows affected (0.00 sec)
mysql> SHOW VARIABLES LIKE 'validate_password%';
+--------------------------------------+--------+
| Variable_name | Value |
+--------------------------------------+--------+
| validate_password_check_user_name | OFF |
| validate_password_dictionary_file | |
| validate_password_length | 4 |
| validate_password_mixed_case_count | 1 |
| validate_password_number_count | 1 |
| validate_password_policy | MEDIUM |
| validate_password_special_char_count | 1 |
+--------------------------------------+--------+
7 rows in set (0.00 sec)
```
关闭密码策略：
```
修改配置文件，添加以下参数：
validate_password=off
```
## 三：数据备份及恢复
#### 1.概述
所有备份数据都应放在非数据库本地，而且建议有多份副本
备份： 能够防止由于机械故障以及人为误操作带来的数据丢失，例如将数据库文件保存在了其它地方
冗余： 数据有多份冗余，但不等备份，只能防止机械故障还来的数据丢失，例如主备模式、数据库集群
备份考虑的因素：
数据的一致性
服务的可用性
分类：
逻辑备份
备份的是建表、建库、插入等操作所执行SQL语句；适用于中小型数据库，效率相对较低（mysqldump）
物理备份
直接复制数据库文件，适用于大型数据库环境，不受存储引擎的限制，但不能恢复到不同的MySQL版本（tar、xtrabackup）
备份方式分类：
完全备份
备份所有数据
增量备份
每次备份上一次备份到现在产生的新数据
差异备份
只备份跟完整备份不一样的
#### 2.tar备份
注意：备份期间，服务不可用
备份过程：完全物理备份
停止数据库
```shell
[root@xingdian ~]# systemctl stop mysqld
```
tar备份数据
```shell
[root@xingdian ~]# mkdir /backup
[root@xingdian ~]# cd /var/lib/mysql
[root@xingdian ~]# tar -zcvf /backup/`date +%F`-mysql-all.tar.gz ./*
```
启动数据库（备份完成后启动数据库，继续为其他服务提供服务）
```shell
[root@xingdian ~]# systemctl start mysqld
```
恢复过程：模拟数据丢失，恢复数据
停止数据库
```shell
[root@xingdian ~]# systemctl stop mysqld
```
清理环境
```shell
[root@xingdian ~]# rm -rf /var/lib/mysql/*
```
导入备份数据
```shell
[root@xingdian ~]# tar -xvf /backup/2019-08-20-mysql-all.tar.gz -C /usr/lib/mysql
[root@xingdian ~]# chown mysql.mysql /var/lib/mysql/* -R
```
启动数据库（恢复后验证数据是否恢复成功）
```shell
[root@xingdian ~]# systemctl start mysqld
```
#### 3.xtrabackup备份
简介：
percona-xtrabackup是开源免费的支持MySQL 数据库热备份的软件；能对InnoDB和XtraDB存储引擎的数据库非阻塞地备份；它不暂停服务创建Innodb热备份；为mysql做增量备份；在mysql服务器之间做在线表迁移；使创建replication更加容易；备份mysql而不增加服务器的负载
安装软件：
```shell
[root@xingdian ~]# yum install https://repo.percona.com/yum/percona-release-latest.noarch.rpm -y
[root@xingdian ~]# yum install percona-xtrabackup-24 -y
```
##### 完整备份
创建备份目录：
```shell
[root@xingdian ~]# mkdir -p /xtrabackup/full/
```
备份：
```shell
[root@xingdian ~]# innobackupex --user=root --password='QianFeng@123' /xtrabackup/full/
```
查看备份数据：
```shell
[root@xingdian ~]# ls /xtrabackup/full/
2022-09-25_19-40-47
```
模拟数据丢失数据恢复：（以下操作模拟数据丢失）
丢失前数据库中的数据：
```shell
[root@xingdian ~]# mysql -u root -pQianFeng@123
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 7
Server version: 5.7.39 MySQL Community Server (GPL)
Copyright (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;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| sys |
| t1 |
+--------------------+
5 rows in set (0.00 sec)
```
数据丢失：
```shell
[root@xingdian ~]# systemctl stop mysqld
[root@xingdian ~]# rm -rf /var/lib/mysql/*
[root@xingdian ~]# rm -rf /var/log/mysqld.log
[root@xingdian ~]# rm -rf /var/log/mysql-slow/slow.log (有则删除，无则不需要操作)
```
恢复前的验证：
```shell
[root@xingdian ~]# innobackupex --apply-log /xtrabackup/full/2022-09-25_19-40-47/
```
恢复之前需要确认配置文件内有数据库目录指定，不然xtrabackup不知道恢复到哪里
```shell
[root@xingdian ~]# cat /etc/my.cnf
datadir=/var/lib/mysql
```
恢复数据：
```shell
[root@xingdian ~]# innobackupex --copy-back /xtrabackup/full/2022-09-25_19-40-47/
```
修改权限：
```shell
[root@xingdian ~]# chown mysql.mysql /var/lib/mysql -R
```
启动服务：
```shell
[root@xingdian ~]# systemctl start mysqld
```
验证：
```shell
[root@xingdian ~]# mysql -u root -pQianFeng@123
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 2
Server version: 5.7.39 MySQL Community Server (GPL)
Copyright (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;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| sys |
| t1 |
+--------------------+
5 rows in set (0.00 sec)
```
##### 增量备份
原理：每次备份上一次备份到现在产生的新数据
注意：在进行增量备份前先进行完整备份
案例：周一进行全备，周二到周天进行增量备份
完整备份：（周一）
```shell
[root@xingdian ~]# innobackupex --user=root --password='QianFeng@123' /xtrabackup/full
```
创建增量备份存放数据目录：
```shell
[root@xingdian ~]# mkdir /xtrabackup/zeng -p
```
模拟数据增加（略）
第一次增量备份：（周二）
```shell
[root@xingdian ~]# innobackupex --user=root --password='QianFeng@123' --incremental /xtrabackup/zeng/ --incremental-basedir=/xtrabackup/full/2022-09-25_19-40-47/
第一次增量备份的数据：
[root@xingdian ~]# ls /xtrabackup/zeng/
2022-09-25_19-56-00
```
模拟数据增加（略）
第二次增量备份：（周三）
```shell
[root@xingdian ~]# innobackupex --user=root --password='QianFeng@123' --incremental /xtrabackup/zeng/ --incremental-basedir=/xtrabackup/zeng/2022-09-25_19-56-00/
第二次增量备份的数据：
[root@xingdian ~]# ls /xtrabackup/zeng/
2022-09-25_19-56-00 2022-09-25_19-58-12
```
后面的增量备份重复上面的操作（略）
增量备份数据恢复流程：（需要模拟数据的丢失）
停止数据库：
```shell
[root@xingdian ~]# systemctl stop mysqld
```
删除数据：
```shell
[root@xingdian ~]# rm -rf /var/lib/mysql/*
[root@xingdian ~]# rm -rf /var/log/mysqld.log
其他数据根据实际情况删除
```
依次重演回滚：
```shell
全备回滚：
[root@xingdian ~]# innobackupex --apply-log --redo-only /xtrabackup/full/2022-09-25_19-40-47/
第一次增量回滚：
[root@xingdian ~]# innobackupex --apply-log --redo-only /xtrabackup/full/2022-09-25_19-40-47/ --incremental-dir=/xtrabackup/zeng/2022-09-25_19-56-00/
第二次增量回滚：
[root@xingdian ~]# innobackupex --apply-log --redo-only /xtrabackup/full/2022-09-25_19-40-47/ --incremental-dir=/xtrabackup/zeng/2022-09-25_19-58-12/
根据实际增量备份的次数回滚，可以想恢复到那个时间节点就回滚到那个时间节点，所有的回滚都给全备
```
恢复数据：
```shell
[root@xingdian ~]# innobackupex --copy-back /xtrabackup/full/2022-09-25_19-40-47/
```
修改权限：
```shell
[root@xingdian ~]# chown mysql.mysql /var/lib/mysql -R
```
启动数据库：
```shell
[root@xingdian ~]# systemctl start mysqld
```
验证：
```shell
[root@xingdian ~]# mysql -u root -pQianFeng@123
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 2
Server version: 5.7.39 MySQL Community Server (GPL)
Copyright (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;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| sys |
| t1 |
| t2 |
| t3 |
+--------------------+
```
##### 差异备份
原理：只备份跟完整备份不一样的
注意：在进行增量备份前先进行完整备份
案例：周一进行全备，周二到周天进行差异备份
完整备份：（周一）
```shell
[root@xingdian ~]# mkdir -p /xtrabackup/full
[root@xingdian ~]# innobackupex --user=root --password=QianFeng@123 /xtrabackup/full
```
模拟数据增加（略）
第一次差异备份：（周二）
```shell
[root@xingdian ~]# mkdir -p /xtrabackup/jian
[root@xingdian ~]# innobackupex --user=root --password=QianFeng@123 --incremental /xtrabackup/jian --incremental-basedir=/xtrabackup/full/2022-09-25_20-10-52/
查看第一次差异备份的数据：
[root@xingdian ~]# ls /xtrabackup/jian/
2022-09-25_20-12-55
```
模拟数据增加（略）
第二次差异备份：（周三）
```shell
[root@xingdian ~]# innobackupex --user=root --password=QianFeng@123 --incremental /xtrabackup/jian --incremental-basedir=/xtrabackup/full/2022-09-25_20-10-52/
查看第二次差异备份的数据：
[root@xingdian ~]# ls /xtrabackup/jian/
2022-09-25_20-12-55 2022-09-25_20-14-32
注意：后面的差异备份跟之前一样，根据需求可以继续差异备份
```
差异备份恢复流程：（模拟数据丢失）
停止数据库：
```shell
[root@xingdian ~]# systemctl stop mysqld
```
删除数据：
```shell
[root@xingdian ~]# rm -rf /var/lib/mysql/*
[root@xingdian ~]# rm -rf /var/log/mysqld.log
```
重演数据回滚：
```shell
完整备份回滚：
[root@xingdian ~]# innobackupex --apply-log --redo-only /xtrabackup/full/2022-09-25_20-10-52/
差异备份回滚（根据差异备份的原理，如果恢复所有数据只需要将最后依次差异回滚）
[root@xingdian ~]# innobackupex --apply-log --redo-only /xtrabackup/full/2022-09-25_20-10-52/ --incremental-dir=/xtrabackup/jian/2022-09-25_20-14-32/
```
恢复数据：
```shell
[root@xingdian ~]# innobackupex --copy-back /xtrabackup/full/2022-09-25_20-10-52/
```
修改权限：
```shell
[root@xingdian ~]# chown mysql.mysql /var/lib/mysql -R
```
启动数据库：
```shell
[root@xingdian ~]# systemctl start mysqld
```
数据验证：
```shell
[root@xingdian ~]# mysql -u root -pQianFeng@123
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 2
Server version: 5.7.39 MySQL Community Server (GPL)
Copyright (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;
+--------------------+
| Database |
+--------------------+
| information_schema |
| k1 |
| k2 |
| mysql |
| performance_schema |
| sys |
+--------------------+
9 rows in set (0.00 sec)
```
#### 4.mysqldump备份
备份表：（前提有库有表）
```shell
[root@xingdian ~]# mysqldump -u root -pQianFeng@123 k1 t1 > /t1.sql
```
恢复表：（恢复之前模拟数据丢失）
```shell
[root@xingdian ~]# mysql -u root -pQianFeng@123 k1 < /t1.sql
mysql: [Warning] Using a password on the command line interface can be insecure.
```
验证：
```shell
[root@xingdian ~]# mysql -u root -pQianFeng@123 -e "use k1;show tables"
mysql: [Warning] Using a password on the command line interface can be insecure.
+--------------+
| Tables_in_k1 |
+--------------+
| t1 |
+--------------+
```
备份一个库：
```shell
[root@xingdian ~]# mysqldump -u root -pQianFeng@123 k1 > /k1.sql
```
备份多个库：
```shell
[root@xingdian ~]# mysqldump -u root -pQianFeng@123 -B k1 k2 > /kall.sql
```
备份所有库：
```shell
[root@xingdian ~]# mysqldump -u root -pQianFeng@123 -A > /all.sql
```
数据恢复：
为保证数据一致性，应在恢复数据之前停止数据库对外的服务,停止binlog日志
binlog使用binlog日志恢复数据时也会产生binlog日志（如果开启的话，需要关闭）
```shell
mysql> set sql_log_bin=0;
Query OK, 0 rows affected (0.00 sec)
```
模拟数据丢失（略）
```shell
[root@xingdian ~]# mysql -u root -pQianFeng@123 -D k1 < /k1.sql
mysql: [Warning] Using a password on the command line interface can be insecure.
ERROR 1049 (42000): Unknown database 'k1'
出现该错误是因为在恢复的时候需要有库的存在
[root@xingdian ~]# mysql -u root -pQianFeng@123 -e "create database k1"
[root@xingdian ~]# mysql -u root -pQianFeng@123 -D k1 < /k1.sql
[root@xingdian ~]# mysql -u root -pQianFeng@123 -e "create database k1"
[root@xingdian ~]# mysql -u root -pQianFeng@123 -e "create database k2"
[root@xingdian ~]# mysql -u root -pQianFeng@123 -D k1 k2 < /kall.sql
或者
mysql> source /k1.sql
```
验证：
```shell
[root@xingdian ~]# mysql -u root -pQianFeng@123 -e "use k1; show tables;"
mysql: [Warning] Using a password on the command line interface can be insecure.
+--------------+
| Tables_in_k1 |
+--------------+
| t1 |
+--------------+
[root@xingdian ~]# mysql -u root -pQianFeng@123 -e "use k2; show tables;"
mysql: [Warning] Using a password on the command line interface can be insecure.
+--------------+
| Tables_in_k2 |
+--------------+
| t1 |
+--------------+
```
#### 5.binlog日志备份
原理：日志方法备份恢复数据
日志默认存储位置：
rpm ： /var/lib/mysql
编译: 安装目录的var下
产生日志：
方式一：编译安装
```shell
[root@xingdian ~]# mysqld_safe --log-bin --user=mysql --server-id=1 &
查看binlog日志
[root@xingdian ~]# mysqlbinlog slave2-bin.000001 -v --base64-output=decode-rows
时间点 ： 141126 14:04:49
位置点 : at 106
```
方式二：rpm安装（永久）
```shell
[root@xingdian ~]# vim /etc/my.cnf
log-bin=mylog
server-id=1 //做主从复制使用
[root@xingdian ~]# systemctl restart mysqld
查看：
[root@xingdian ~]# ls /var/lib/mysql
auto.cnf client-key.pem ib_logfile1 mysql private_key.pem sys
ca-key.pem ib_buffer_pool ibtmp1 mysql.sock public_key.pem xingdian-bin.index
ca.pem ibdata1 mylog.000001 mysql.sock.lock server-cert.pem xtrabackup_info
client-cert.pem ib_logfile0 mylog.index
[root@xingdian ~]# mysqlbinlog /var/lib/mysql/mylog.000001 -v --base64-output=decode-rows
/*!50530 SET @@SESSION.PSEUDO_SLAVE_MODE=1*/;
/*!50003 SET @OLD_COMPLETION_TYPE=@@COMPLETION_TYPE,COMPLETION_TYPE=0*/;
DELIMITER /*!*/;
# at 4
#220925 21:12:47 server id 1 end_log_pos 123 CRC32 0x52358645 Start: binlog v 4, server v 5.7.39-log created 220925 21:12:47 at startup
# Warning: this binlog is either in use or was not closed properly.
ROLLBACK/*!*/;
# at 123
#220925 21:12:47 server id 1 end_log_pos 154 CRC32 0xa84d8536 Previous-GTIDs
# [empty]
# at 154
#220925 21:13:38 server id 1 end_log_pos 219 CRC32 0xc2b00431 Anonymous_GTID last_committed=0 sequence_number=1 rbr_only=no
SET @@SESSION.GTID_NEXT= 'ANONYMOUS'/*!*/;
# at 219
#220925 21:13:38 server id 1 end_log_pos 307 CRC32 0x635401a5 Query thread_id=2 exec_time=0 error_code=0
SET TIMESTAMP=1664111618/*!*/;
SET @@session.pseudo_thread_id=2/*!*/;
SET @@session.foreign_key_checks=1, @@session.sql_auto_is_null=0, @@session.unique_checks=1, @@session.autocommit=1/*!*/;
SET @@session.sql_mode=1436549152/*!*/;
SET @@session.auto_increment_increment=1, @@session.auto_increment_offset=1/*!*/;
/*!\C utf8 *//*!*/;
SET @@session.character_set_client=33,@@session.collation_connection=33,@@session.collation_server=8/*!*/;
SET @@session.lc_time_names=0/*!*/;
SET @@session.collation_database=DEFAULT/*!*/;
create database t1
/*!*/;
SET @@SESSION.GTID_NEXT= 'AUTOMATIC' /* added by mysqlbinlog */ /*!*/;
DELIMITER ;
# End of log file
/*!50003 SET COMPLETION_TYPE=@OLD_COMPLETION_TYPE*/;
/*!50530 SET @@SESSION.PSEUDO_SLAVE_MODE=0*/;
方法二：
mysql> show binlog events in "mylog.000001";
+--------------+-----+----------------+-----------+-------------+---------------------------------------+
| Log_name | Pos | Event_type | Server_id | End_log_pos | Info |
+--------------+-----+----------------+-----------+-------------+---------------------------------------+
| mylog.000001 | 4 | Format_desc | 1 | 123 | Server ver: 5.7.39-log, Binlog ver: 4 |
| mylog.000001 | 123 | Previous_gtids | 1 | 154 | |
| mylog.000001 | 154 | Anonymous_Gtid | 1 | 219 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' |
| mylog.000001 | 219 | Query | 1 | 307 | create database t1 |
+--------------+-----+----------------+-----------+-------------+---------------------------------------+
4 rows in set (0.00 sec)
默认查看第一个
mysql> show binlog events;
+--------------+-----+----------------+-----------+-------------+---------------------------------------+
| Log_name | Pos | Event_type | Server_id | End_log_pos | Info |
+--------------+-----+----------------+-----------+-------------+---------------------------------------+
| mylog.000001 | 4 | Format_desc | 1 | 123 | Server ver: 5.7.39-log, Binlog ver: 4 |
| mylog.000001 | 123 | Previous_gtids | 1 | 154 | |
| mylog.000001 | 154 | Anonymous_Gtid | 1 | 219 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' |
| mylog.000001 | 219 | Query | 1 | 307 | create database t1 |
+--------------+-----+----------------+-----------+-------------+---------------------------------------+
4 rows in set (0.00 sec)
```
数据恢复：
根据时间点恢复数据：
```shell
[root@xingdian ~]# mysqlbinlog --start-datetime='2022-9-25 21:12:47' --stop-datetime='2022-9-25 21:16:55' /var/lib/mysql/mylog.000001 | mysql -u root -pQianFeng@123
```
根据位置点恢复数据：
```shell
mysql> show binlog events;
+--------------+-----+----------------+-----------+-------------+---------------------------------------+
| Log_name | Pos | Event_type | Server_id | End_log_pos | Info |
+--------------+-----+----------------+-----------+-------------+---------------------------------------+
| mylog.000001 | 4 | Format_desc | 1 | 123 | Server ver: 5.7.39-log, Binlog ver: 4 |
| mylog.000001 | 123 | Previous_gtids | 1 | 154 | |
| mylog.000001 | 154 | Anonymous_Gtid | 1 | 219 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' |
| mylog.000001 | 219 | Query | 1 | 307 | create database t1 |
| mylog.000001 | 307 | Anonymous_Gtid | 1 | 372 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' |
| mylog.000001 | 372 | Query | 1 | 453 | drop database t1 |
| mylog.000001 | 453 | Anonymous_Gtid | 1 | 518 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' |
| mylog.000001 | 518 | Query | 1 | 606 | create database t1 |
| mylog.000001 | 606 | Anonymous_Gtid | 1 | 671 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' |
| mylog.000001 | 671 | Query | 1 | 752 | drop database t1 |
+--------------+-----+----------------+-----------+-------------+---------------------------------------+
[root@xingdian ~]# mysqlbinlog --start-position 219 --stop-position 307 /var/lib/mysql/mylog.000001 | mysql -u root -pQianFeng@123
```