mysql 逻辑备份 bin-log日志恢复

一、逻辑备份

逻辑备份：备份的是建表，建库，插入数据等操作所执行SQL语句，适用于中小型数据库，效率相对较低，提供三种级别的备份，表级，库级和全库级。

本质：导出的是SQL语句

优点：不论是什么存储引擎，都可以用mysqldump备份成SQL语句

缺点：速度较慢，导出时可能会出现格式不兼容的突发状况，无法做增量备份和累计增量备份

数据一致，服务可用:如何保证数据一致，在备份的时候进行锁表会自动锁表。锁住之后在备份。

二、逻辑备份：

1、备份全部数据库

语法：mysqldump -u指定用户 -p指定密码 -A > 文件名

mysqldump -u指定用户 -p指定密码 --all-databases > 文件名

[root@localhost ~]#  mysqldump -uroot -p123 -A > all.mysql
 mysqldump: [Warning] Using a password on the command line interface can be insecure.

[root@localhost ~]# mysqldump -uroot -p123 --all-database >all1.txt
mysqldump: [Warning] Using a password on the command line interface can be insecure.

2.备份部分数据库

语法：mysqldump -u指定用户 -p密码 -B 数据库名1 数据库名2> 文件名

mysqldump -u指定用户 -p密码 --databases 数据库名1 数据库名2 > 文件名

[root@localhost ~]# mysqldump -uroot -p123 -B db1 >db1.txt
mysqldump: [Warning] Using a password on the command line interface can be insecure.

[root@localhost ~]# mysqldump -uroot -p123 --databases db1 school > db2.txt 
mysqldump: [Warning] Using a password on the command line interface can be insecure.

3.备份表

语法：mysqldump -u指定用户 -p指定密码数据库名表名 > 文件名

[root@localhost ~]# mysqldump -uroot -p123 db1 employee > employee.txt
mysqldump: [Warning] Using a password on the command line interface can be insecure.

4.备份表结构

语法：mysqldump -u指定用户 -p指定密码 -d 数据库名表名

[root@localhost ~]# mysqldump -uroot -p123 -d db1 employee > jiegou.txt
mysqldump: [Warning] Using a password on the command line interface can be insecure.

5.备份表数据

语法：select * from 表.库 into outfile'/var/lib/mysql-files/文件名'；

mysql> show variables like 'secure%'; #查看默认导出路径
+------------------+-----------------------+
| Variable_name    | Value                 |
+------------------+-----------------------+
| secure_auth      | ON                    |
| secure_file_priv | /var/lib/mysql-files/ |
+------------------+-----------------------+
2 rows in set (0.00 sec)

mysql> select * from mysql.user into outfile '/var/lib/mysql-files/b.xfs';  
Query OK, 6 rows affected (0.00 sec)

扩展：修改默认的导出路径

[root@localhost opt]# mkdir backup #创建默认目录
[root@localhost opt]# chown -R mysql.mysql /opt/backup#修改目录的属主和属组
[root@localhost opt]# vim /etc/my.cnf  #修改配置文件
secure_file_priv=/opt/backup
[root@localhost opt]# systemctl restart mysqld #重启mysql

[root@localhost opt]# mysql -p123 #进入mysql
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.7.43 MySQL Community Server (GPL)

Copyright (c) 2000, 2023, 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 variables like 'secure%'; #再次查看文件的默认路径
+------------------+--------------+
| Variable_name    | Value        |
+------------------+--------------+
| secure_auth      | ON           |
| secure_file_priv | /opt/backup/ |
+------------------+--------------+
2 rows in set (0.01 sec)

6.恢复

（1）命令行恢复数据库

a)命令行恢复

语法：mysql -u用户名 -p密码 < 之前备份的文件

mysql> drop  database db1;    #先删除数据库db1
Query OK, 15 rows affected (0.07 sec)
mysql> show databases;   #查看数据库
+--------------------+
| Database           |
+--------------------+
| information_schema |
| db3                |
| mysql              |
| performance_schema |
| school             |
| sys                |
+--------------------+
6 rows in set (0.00 sec)

[root@localhost ~]# mysql -uroot -p123 < db1.txt #恢复数据库
mysql: [Warning] Using a password on the command line interface can be insecure.
mysql> show databases;    #再次查看数据库
+--------------------+
| Database           |
+--------------------+
| information_schema |
| db1                |
| db3                |
| mysql              |
| performance_schema |
| school             |
| sys                |
+--------------------+
7 rows in set (0.00 sec)

b)数据库里面恢复

语法：source +备份数据库的路径

mysql> drop database db1;  #删除数据库db1
Query OK, 15 rows affected (0.05 sec)

mysql> source /root/db1.txt #恢复数据库db1
Query OK, 0 rows affected (0.00 sec)

.
.

Query OK, 0 rows affected (0.00 sec)


mysql> show databases; #查看数据库
+--------------------+
| Database           |
+--------------------+
| information_schema |
| db1                |
| db3                |
| mysql              |
| performance_schema |
| school             |
| sys                |
+--------------------+
7 rows in set (0.00 sec)

（2）恢复表

a)在命令行恢复

语法：mysql -u用户 -p密码表所在的数据库< 备份的文件

[root@localhost ~]# mysql -uroot -p123  db1< employee.txt
mysql: [Warning] Using a password on the command line interface can be insecure.

b)在数据库里面恢复

语法：source +备份的路径

mysql> source /root/employee.txt
Query OK, 0 rows affected (0.00 sec)

Query OK, 0 rows affected (0.00 sec)

（3）恢复表结构

语法：mysql -u用户 -p密码 -D 数据库名 < 备份的文件

[root@localhost ~]# mysql -uroot -p123 -D db1 <jiegou.txt
mysql: [Warning] Using a password on the command line interface can be insecure.

mysql> desc employee;
+-----------------+---------------------+------+-----+---------+----------------+
| Field           | Type                | Null | Key | Default | Extra          |
+-----------------+---------------------+------+-----+---------+----------------+
| id              | int(11)             | NO   | PRI | NULL    | auto_increment |
| name            | varchar(30)         | NO   |     | NULL    |                |
| sex             | enum('man','woman') | YES  |     | man     |                |
| hire_date       | date                | YES  |     | NULL    |                |
| post            | varchar(20)         | YES  |     | NULL    |                |
| job_description | varchar(100)        | YES  |     | NULL    |                |
| salary          | double(15,2)        | NO   |     | NULL    |                |
| office          | int(11)             | YES  |     | NULL    |                |
| dep_id          | int(11)             | YES  |     | NULL    |                |
+-----------------+---------------------+------+-----+---------+----------------+
9 rows in set (0.00 sec)

mysql> select * from employee;
Empty set (0.00 sec)

（4）恢复表中数据

mysql> truncate employee;   #清空表中数据
Query OK, 0 rows affected (0.02 sec)

mysql> select * from employee; #查看表中数据
Empty set (0.00 sec)

mysql> load data infile'/opt/backup/a.txt'into table employee;
Query OK, 15 rows affected (0.01 sec)
Records: 15  Deleted: 0  Skipped: 0  Warnings: 0

mysql> select * from employee;
+----+-----------+-------+------------+------------+-----------------+----------+--------+--------+
| id | name      | sex   | hire_date  | post       | job_description | salary   | office | dep_id |
+----+-----------+-------+------------+------------+-----------------+----------+--------+--------+
|  1 | qiancheng | man   | 2018-03-14 | hr         | talk            |  7000.00 |    501 |    102 |
| 20 | tom       | man   | 2017-09-15 | instructor | teach           |  8000.00 |    501 |    100 |
| 21 | alince    | woman | 2013-04-28 | instructor | teach           |  5500.00 |    501 |    100 |
| 22 | robin     | man   | 2020-09-18 | instructor | teach           |  7200.00 |    501 |    100 |
| 23 | zhuzhu    | man   | 2016-12-09 | hr         | hrcc            |  6000.00 |    502 |    101 |
| 24 | gougou    | woman | 2015-04-27 | hr         | NULL            |  6000.00 |    502 |    101 |
| 30 | maomao    | man   | 2019-08-12 | sale       | talk            | 20000.00 |    503 |    102 |
| 31 | yiyi      | man   | 2015-06-17 | talk       | NULL            |  8000.00 |   NULL |   NULL |
| 40 | harry     | woman | 2018-02-05 | hr         | hrcc            |  6900.00 |    502 |    102 |
| 41 | tianyuan  | man   | 2018-02-05 | null       | salecc          |  9700.00 |    501 |    102 |
| 42 | xiaoyi    | man   | 2018-02-05 | null       | salecc          |  5700.00 |    501 |    102 |
| 50 | zxvb      | man   | 2019-04-23 | hr         | NULL            |  8000.00 |   NULL |   NULL |
| 51 | ab        | man   | NULL       | NULL       | NULL            |  6500.00 |   NULL |   NULL |
| 52 | cd        | man   | NULL       | NULL       | NULL            |  7600.00 |   NULL |   NULL |
| 53 | ef        | man   | NULL       | NULL       | NULL            |  8900.00 |   NULL |   NULL |
+----+-----------+-------+------------+------------+-----------------+----------+--------+--------+
15 rows in set (0.00 sec)

三、bin-log 日志恢复数据

1.开启binlog日志功能

(1）.修改配置文件

[root@localhost ~]# vim /etc/my.cnf
server-id=1        #添加server-id 
log-bin = /opt/log/mysql-bin.log #指定binlog日志文件的存放位置和名称，位置和名称都可以自定义

(2).修改/opt/log属主属组

[root@localhost ~]# chown -R mysql.mysql /opt/log

(3).重启mysql服务,使修改的配置文件生效

[root@localhost ~]# systemctl restart mysqld
[root@localhost ~]# cd /opt/log
[root@localhost log]# ls
mysql-bin.000001  mysql-bin.index

2.刷新binlog日志

mysql> flush logs;				#刷新binlog日志，使下面的语句存放到下一个binlog日志中

3.查看当前存储的binlog文件

mysql> show master status;
+------------------+----------+--------------+------------------+-------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000002 |      154 |              |                  |                   |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)

4.恢复数据

案例：不小心删除了数据库中的一张表及其数据

（1）进入binlog文件的目录，查看bin-log文件

[root@localhost ~]# cd /opt/log
[root@localhost log]# ls
mysql-bin.000001   mysql-bin.000002 mysql-bin.index
[root@localhost log]# mysqlbinlog mysql-bin.000002 --base64-output=decode-rows -vv
/*!50530 SET @@SESSION.PSEUDO_SLAVE_MODE=1*/;
/*!50003 SET @OLD_COMPLETION_TYPE=@@COMPLETION_TYPE,COMPLETION_TYPE=0*/;
DELIMITER /*!*/;
# at 4
#231007 19:40:11 server id 1  end_log_pos 123 CRC32 0xa788ae39     Start: binlog v 4, server v 5.7.43-log created 231007 19:40:11
# Warning: this binlog is either in use or was not closed properly.
# at 123
#231007 19:40:11 server id 1  end_log_pos 154 CRC32 0xd228507b     Previous-GTIDs
# [empty]
# at 154
#231007 19:45:19 server id 1  end_log_pos 219 CRC32 0xdf49c909     Anonymous_GTID  last_committed=0        sequence_number=1  rbr_only=no
SET @@SESSION.GTID_NEXT= 'ANONYMOUS'/*!*/;
# at 219
#231007 19:45:19 server id 1  end_log_pos 329 CRC32 0x7f94b39e     Query   thread_id=3     exec_time=0     error_code=0
SET TIMESTAMP=1696679119/*!*/;
SET @@session.pseudo_thread_id=3/*!*/;
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 db default charset'utf8'
/*!*/;
# at 329
#231007 19:46:20 server id 1  end_log_pos 394 CRC32 0xc79d4673     Anonymous_GTID  last_committed=1        sequence_number=2  rbr_only=no
SET @@SESSION.GTID_NEXT= 'ANONYMOUS'/*!*/;
# at 394
#231007 19:46:20 server id 1  end_log_pos 513 CRC32 0xeca5dcea     Query   thread_id=3     exec_time=0     error_code=0
use `db`/*!*/;
SET TIMESTAMP=1696679180/*!*/;
create table db1(id int,name varchar(30),age int)
/*!*/;
# at 513
#231007 19:47:58 server id 1  end_log_pos 578 CRC32 0x502f26e0     Anonymous_GTID  last_committed=2        sequence_number=3  rbr_only=yes
/*!50718 SET TRANSACTION ISOLATION LEVEL READ COMMITTED*//*!*/;
SET @@SESSION.GTID_NEXT= 'ANONYMOUS'/*!*/;
# at 578
#231007 19:47:58 server id 1  end_log_pos 648 CRC32 0x1c085c1f     Query   thread_id=3     exec_time=0     error_code=0
SET TIMESTAMP=1696679278/*!*/;
BEGIN
/*!*/;
# at 648
#231007 19:47:58 server id 1  end_log_pos 696 CRC32 0x836eb6d7     Table_map: `db`.`db1` mapped to number 109
# at 696
#231007 19:47:58 server id 1  end_log_pos 784 CRC32 0x9580d081     Write_rows: table id 109 flags: STMT_END_F
### INSERT INTO `db`.`db1`
### SET
###   @1=1 /* INT meta=0 nullable=1 is_null=0 */
###   @2='xiaoli' /* VARSTRING(90) meta=90 nullable=1 is_null=0 */
###   @3=23 /* INT meta=0 nullable=1 is_null=0 */
### INSERT INTO `db`.`db1`
### SET
###   @1=2 /* INT meta=0 nullable=1 is_null=0 */
###   @2='xiaozhang' /* VARSTRING(90) meta=90 nullable=1 is_null=0 */
###   @3=34 /* INT meta=0 nullable=1 is_null=0 */
### INSERT INTO `db`.`db1`
### SET
###   @1=3 /* INT meta=0 nullable=1 is_null=0 */
###   @2='zhangsan' /* VARSTRING(90) meta=90 nullable=1 is_null=0 */
###   @3=42 /* INT meta=0 nullable=1 is_null=0 */
# at 784
#231007 19:47:58 server id 1  end_log_pos 815 CRC32 0xe927fd1d     Xid = 12
COMMIT/*!*/;
# at 815
#231007 19:48:10 server id 1  end_log_pos 880 CRC32 0xcdc9d73a     Anonymous_GTID  last_committed=3        sequence_number=4  rbr_only=yes
/*!50718 SET TRANSACTION ISOLATION LEVEL READ COMMITTED*//*!*/;
SET @@SESSION.GTID_NEXT= 'ANONYMOUS'/*!*/;
# at 880
#231007 19:48:10 server id 1  end_log_pos 950 CRC32 0x0a8ade69     Query   thread_id=3     exec_time=0     error_code=0
SET TIMESTAMP=1696679290/*!*/;
BEGIN
/*!*/;
# at 950
#231007 19:48:10 server id 1  end_log_pos 998 CRC32 0x68b7b908     Table_map: `db`.`db1` mapped to number 109
# at 998
#231007 19:48:10 server id 1  end_log_pos 1086 CRC32 0xc1c77e9d    Delete_rows: table id 109 flags: STMT_END_F
### DELETE FROM `db`.`db1`
### WHERE
###   @1=1 /* INT meta=0 nullable=1 is_null=0 */
###   @2='xiaoli' /* VARSTRING(90) meta=90 nullable=1 is_null=0 */
###   @3=23 /* INT meta=0 nullable=1 is_null=0 */
### DELETE FROM `db`.`db1`
### WHERE
###   @1=2 /* INT meta=0 nullable=1 is_null=0 */
###   @2='xiaozhang' /* VARSTRING(90) meta=90 nullable=1 is_null=0 */
###   @3=34 /* INT meta=0 nullable=1 is_null=0 */
### DELETE FROM `db`.`db1`
### WHERE
###   @1=3 /* INT meta=0 nullable=1 is_null=0 */
###   @2='zhangsan' /* VARSTRING(90) meta=90 nullable=1 is_null=0 */
###   @3=42 /* INT meta=0 nullable=1 is_null=0 */
# at 1086
#231007 19:48:10 server id 1  end_log_pos 1117 CRC32 0x6cca4c23    Xid = 13
COMMIT/*!*/;
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*/;

3.找到要恢复的起始位置，和结束位置

由题可知要恢复的起始位置和结束位置分别为648,950

[root@localhost log]# mysqlbinlog --start-position 648 --stop-position 950 mysql-bin.000002 |mysql -uroot -p123
mysql: [Warning] Using a password on the command line interface can be insecure.

4.进入数据库查看数据是否恢复

mysql> select * from  db.db1;
+------+-----------+------+
| id   | name      | age  |
+------+-----------+------+
|    1 | xiaoli    |   23 |
|    2 | xiaozhang |   34 |
|    3 | zhangsan  |   42 |
+------+-----------+------+
3 rows in set (0.00 sec)

扩展：根据binlog日志的时间点恢复

[root@localhost log]# mysqlbinlog --start-datetime='2023-10-07 19:47:58' --stop-datetime='2023-10-07 19:48:10' mysql-bin.000002 |mysql -uroot -p123
mysql: [Warning] Using a password on the command line interface can be insecure.

mysql> select * from db.db1;
+------+-----------+------+
| id   | name      | age  |
+------+-----------+------+
|    1 | xiaoli    |   23 |
|    2 | xiaozhang |   34 |
|    3 | zhangsan  |   42 |
+------+-----------+------+
3 rows in set (0.00 sec)