详解MySQL误操作后怎样进行数据恢复

时间:2020-12-15 Martin 人气:3

在大家日常操作数据库时候难免会因为“大意”而误操作，那么误操作后怎样进行数据恢复呢，下面跟着小编一起来学习学习。

一、开启binlog。

首先查看binlog是否开启

mysql> show variables like "log_bin";
+---------------+-------+
|Variable_name | Value 
+---------------+-------+
| log_bin  OFF 
+---------------+-------+
1 row in set (0.00 sec)

值为OFF，需开启，开启binlog方式如下：

#vim /etc/my.cnf

在[mysqld]中加入

log-bin     = mysql-bin
log-bin     = /usr/local/mysql/log/mysql-bin.log

重启mysql服务

#service mysqld stop
#service mysqld start

二、模拟数据写入

建库

create database backup;

建表

CREATE TABLE `number` (
 `id` int(11) NOT NULL AUTO_INCREMENT COMMENT '编号',
 `updatetime` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
 PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

写入数据

程序2-1

#coding:utf8
#python2.7
import MySQLdb
import time
def connect_mysql(db_host="192.168.11.169",user="martin",passwd="martin",db="backup",charset="utf8"):
 conn = MySQLdb.connect(host=db_host,user=user,passwd=passwd,db=db,charset=charset)
 conn.autocommit(True)
return conn.cursor()
#数据插入
for i in range(0,10):
#time=time.strftime("%Y-%m-%d %H:%M:%S")
sql = 'insert into number(updatetime) values(%s)'
values = [(time.strftime("%Y-%m-%d %H:%M:%S"))]
 db1 = connect_mysql()
print db1.executemany(sql,values)

查询数据

mysql> select * from number;
+-------+------------------------+
| id | updatetime   
+--------------------------------+
| 1 | 2016-06-29 23:27:15 |
| 2 | 2016-06-29 23:27:15 |
| 3 | 2016-06-29 23:27:15 |
| 4 | 2016-06-29 23:27:15 |
| 5 | 2016-06-29 23:27:15 |
| 6 | 2016-06-29 23:27:15 |
| 7 | 2016-06-29 23:27:15 |
| 8 | 2016-06-29 23:27:15 |
| 9 | 2016-06-29 23:27:15 |
| 10 | 2016-06-29 23:27:15 |
+-------+------------------------+
10 rows in set (0.00 sec)

三、全量备份

mysqldump -uroot -p -F --master-data=2 backup |gzip> /martin/data/backup_$(date +%F).sql.gz

注：加-F能刷新binlog，方便恢复时操作。

四、模拟写入增量数据

继续执行程序2-1。

查询数据

mysql> select * from number;
+----+---------------------------+
| id | updatetime   |
+----+---------------------------+
| 1 | 2016-06-29 23:27:15 |
| 2 | 2016-06-29 23:27:15 |
| 3 | 2016-06-29 23:27:15 |
| 4 | 2016-06-29 23:27:15 |
| 5 | 2016-06-29 23:27:15 |
| 6 | 2016-06-29 23:27:15 |
| 7 | 2016-06-29 23:27:15 |
| 8 | 2016-06-29 23:27:15 |
| 9 | 2016-06-29 23:27:15 |
| 10 | 2016-06-29 23:27:15 |
| 11 | 2016-06-29 23:31:03 |
| 12 | 2016-06-29 23:31:03 |
| 13 | 2016-06-29 23:31:03 |
| 14 | 2016-06-29 23:31:03 |
| 15 | 2016-06-29 23:31:03 |
| 16 | 2016-06-29 23:31:03 |
| 17 | 2016-06-29 23:31:03 |
| 18 | 2016-06-29 23:31:03 |
| 19 | 2016-06-29 23:31:03 |
| 20 | 2016-06-29 23:31:03 |
+-------+---------------------+
20 rows in set (0.00 sec)

五、增量备份

保留mysql-bin.000002及之后的binlog即可。

六、模拟误操作

delete from number;

七、再次写入增量数据

执行程序2-1

select * from bumber;

+------+------------------------+
| id | updatetime   |
+------+------------------------+
| 21 | 2016-06-29 23:41:06 |
| 22 | 2016-06-29 23:41:06 |
| 23 | 2016-06-29 23:41:06 |
| 24 | 2016-06-29 23:41:06 |
| 25 | 2016-06-29 23:41:06 |
| 26 | 2016-06-29 23:41:06 |
| 27 | 2016-06-29 23:41:06 |
| 28 | 2016-06-29 23:41:06 |
| 29 | 2016-06-29 23:41:06 |
| 30 | 2016-06-29 23:41:06 |
+------+------------------------+
10 rows in set (0.00 sec)

八、恢复

此时发现之前的delete操作为误操作，急需恢复，恢复过程如下

给该表加上读锁

lock table number read;

将全量备份的数据导入

#cd /martin/data/
#gzip -d number_2016-06-29.sql.gz
#grep -i "change" *.sql
-- CHANGE MASTER TO MASTER_LOG_FILE='mysql-bin.000002', MASTER_LOG_POS=107;

刷新日志

#mysqladmin -uroot -p'martin' flush-logs
#cd /usr/local/mysql/log
#ls|grep mysql-bin|grep -v index
mysql-bin.000001
mysql-bin.000002
mysql-bin.000003

可确定mysql-bin.000002为增量数据binlog

导入全量备份

#cd /martin/data/
#mysql -uroot -p backup < number_2016-06-29.sql
#cp /usr/local/mysql/log/mysql-bin.000002 /martin/data/
#mysqlbinlog mysql-bin.000002 >bin.sql
#vim bin.sql

在bin.sql找到之前的delete语句，删除

mysql -uroot -p <bin.sql

九、确认已恢复数据

登录mysql

#mysql -uroot -p'martin' backup
select * from number;

+----+---------------------+
| id | updatetime   |
+----+---------------------+
| 1 | 2016-06-29 23:27:15 |
| 2 | 2016-06-29 23:27:15 |
| 3 | 2016-06-29 23:27:15 |
| 4 | 2016-06-29 23:27:15 |
| 5 | 2016-06-29 23:27:15 |
| 6 | 2016-06-29 23:27:15 |
| 7 | 2016-06-29 23:27:15 |
| 8 | 2016-06-29 23:27:15 |
| 9 | 2016-06-29 23:27:15 |
| 10 | 2016-06-29 23:27:15 |
| 11 | 2016-06-29 23:31:03 |
| 12 | 2016-06-29 23:31:03 |
| 13 | 2016-06-29 23:31:03 |
| 14 | 2016-06-29 23:31:03 |
| 15 | 2016-06-29 23:31:03 |
| 16 | 2016-06-29 23:31:03 |
| 17 | 2016-06-29 23:31:03 |
| 18 | 2016-06-29 23:31:03 |
| 19 | 2016-06-29 23:31:03 |
| 20 | 2016-06-29 23:31:03 |
| 21 | 2016-06-29 23:41:06 |
| 22 | 2016-06-29 23:41:06 |
| 23 | 2016-06-29 23:41:06 |
| 24 | 2016-06-29 23:41:06 |
| 25 | 2016-06-29 23:41:06 |
| 26 | 2016-06-29 23:41:06 |
| 27 | 2016-06-29 23:41:06 |
| 28 | 2016-06-29 23:41:06 |
| 29 | 2016-06-29 23:41:06 |
| 30 | 2016-06-29 23:41:06 |
+----+---------------------+
30 rows in set (0.00 sec)

恢复完成！以上就是本文的全部内容，在操作数据库时候要多加小心尽量避免误操作，如果万一遇到了，希望本文能够帮助大家。

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