《Mysql实例MySQL中truncate误操作后的数据恢复案例》要点：
本文介绍了Mysql实例MySQL中truncate误操作后的数据恢复案例，希望对您有用。如果有疑问，可以联系我们。
MYSQL学习实际线上的场景比较复杂,当时涉及了truncate, delete 两个操作,经确认丢数据差不多7万多行,等停下来时,差不多又有共计1万多行数据写入. 这里为了简单说明,只拿弄一个简单的业务场景举例.
MYSQL学习测试环境： Percona-Server-5.6.16
日志格式： mixed 没起用gtid
MYSQL学习表结构如下：
MYSQL学习
CREATE TABLE `tb_wubx` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`name` varchar(32) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8
CREATE TABLE `tb_wubx` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`name` varchar(32) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8
MYSQL学习基于某个时间点有一个备份或是有全量的binlog是能恢复数据的一个唯一保证. 例如我们的备份就是一个表结构创建语句,binlog pos相关信息： mysql-bin.000004 , 4,然后进行了如下：
MYSQL学习Ct1时间 程序写入：
MYSQL学习
insert into tb_wubx(name) values(‘张三'),(‘李四');
insert into tb_wubx(name) values(‘隔壁老王');
MYSQL学习Ct2时间 某个人员失误
MYSQL学习
truncate table tb_wubx;
MYSQL学习Ct3时间 程序写入
MYSQL学习
insert into tb_wubx(name) values(‘老赵');
update tb_wubx set name='老赵赵' where id=1;
MYSQL学习现在表里的数据情况：
MYSQL学习
mysql>select * from tb_wubx;
+----+-----------+
| id | name |
+----+-----------+
| 1 | 老赵赵 |
+----+-----------+
1 row in set (0.00 sec)
mysql>select * from tb_wubx;
+----+-----------+
| id | name |
+----+-----------+
| 1 | 老赵赵 |
+----+-----------+
1 row in set (0.00 sec)
MYSQL学习可以见truncate table操作后,表的自增id又变更为从1开始,原来写入的数据应该是：
MYSQL学习
+―-+―――C+
| id | name |
+―-+―――C+
| 1 | 张三 |
+―-+―――C+
| 2 | 李四 |
+―-+―――C+
| 3 | 隔壁老王 |
+―-+―――C+
MYSQL学习如果没生truncate table操作,实际的数据应该为：
MYSQL学习
+―-+―――C+
| id | name |
+―-+―――C+
| 1 | 张三 |
+―-+―――C+
| 2 | 李四 |
+―-+―――C+
| 3 | 隔壁老王 |
+―-+―――C+
| 4 | 老赵赵 |
+―-+―――C+
MYSQL学习而且线上的恢复那个表时和序序开发人员了解才知道,原来那个id和缓存及其它地方有依赖,因为id乱了,也会造成程序错乱.这个时间修复id在程序层错乱的事,留给开发人员了关建是给他们讲明白恢复的结果是什么样,我们的关建任务是把数据恢复出来.好,接下来的工作是开始从binlog中恢复数据.
利用: show binary logs; 查看当的log文件分布, 然后利用show binlog events in ‘binary log文件'; 查看log文件的内容,目的是找到truncate发生的日志位置.
另外因为基于备份(由log的启始位置)或是从量log, 如果基于备份有log的起始位置,我们需要处理的log文件是启始位置到发生truncate的日值(后面的数据处理不了,会发生主建冲突的错误造成truncate后的数据不能恢复),
如果是全量日志,需要从创建完mysql后库后的日志去处理到当前的发生truncate的位置(后面数据会因为主建冲突写不进去)
恢复准备工作,创建一个库用于恢复数据,这里创建了一个re_wubx, 及原结构的表: tb_wubx (相当于恢复了备份,过程省略)
MYSQL学习
mysql> show binary logs;
+------------------+-----------+
| Log_name | File_size |
+------------------+-----------+
| mysql-bin.000001 | 143 |
| mysql-bin.000002 | 261 |
| mysql-bin.000003 | 562 |
| mysql-bin.000004 | 1144 |
+------------------+-----------+
4 rows in set (0.00 sec)
mysql> show binary logs;
+------------------+-----------+
| Log_name | File_size |
+------------------+-----------+
| mysql-bin.000001 | 143 |
| mysql-bin.000002 | 261 |
| mysql-bin.000003 | 562 |
| mysql-bin.000004 | 1144 |
+------------------+-----------+
4 rows in set (0.00 sec)
MYSQL学习我这里有一个备份文件就是那个创建表的sql语句,位置是mysql-bin.000004 , 4
在这个案例里我只用cover住mysql-bin.000004这个文件.
MYSQL学习
mysql>show binlog events in 'mysql-bin.000004';
+------------------+------+-------------+-----------+-------------+----------------------------------------------------+
| Log_name | Pos | Event_type | Server_id | End_log_pos | Info |
+------------------+------+-------------+-----------+-------------+----------------------------------------------------+
| mysql-bin.000004 | 4 | Format_desc | 753306 | 120 | Server ver: 5.6.16-64.2-rel64.2-log, Binlog ver: 4 |
| mysql-bin.000004 | 120 | Query | 753306 | 209 | use `wubx`; truncate table tb_wubx |
| mysql-bin.000004 | 209 | Query | 753306 | 281 | BEGIN |
| mysql-bin.000004 | 281 | Table_map | 753306 | 334 | table_id: 91 (wubx.tb_wubx) |
| mysql-bin.000004 | 334 | Write_rows | 753306 | 393 | table_id: 91 flags: STMT_END_F |
| mysql-bin.000004 | 393 | Xid | 753306 | 424 | COMMIT /* xid=1073 */ |
| mysql-bin.000004 | 424 | Query | 753306 | 496 | BEGIN |
| mysql-bin.000004 | 496 | Table_map | 753306 | 549 | table_id: 91 (wubx.tb_wubx) |
| mysql-bin.000004 | 549 | Write_rows | 753306 | 602 | table_id: 91 flags: STMT_END_F |
| mysql-bin.000004 | 602 | Xid | 753306 | 633 | COMMIT /* xid=1074 */ |
| mysql-bin.000004 | 633 | Query | 753306 | 722 | use `wubx`; truncate table tb_wubx |
| mysql-bin.000004 | 722 | Query | 753306 | 794 | BEGIN |
| mysql-bin.000004 | 794 | Table_map | 753306 | 847 | table_id: 92 (wubx.tb_wubx) |
| mysql-bin.000004 | 847 | Write_rows | 753306 | 894 | table_id: 92 flags: STMT_END_F |
| mysql-bin.000004 | 894 | Xid | 753306 | 925 | COMMIT /* xid=1081 */ |
| mysql-bin.000004 | 925 | Query | 753306 | 997 | BEGIN |
| mysql-bin.000004 | 997 | Table_map | 753306 | 1050 | table_id: 92 (wubx.tb_wubx) |
| mysql-bin.000004 | 1050 | Update_rows | 753306 | 1113 | table_id: 92 flags: STMT_END_F |
| mysql-bin.000004 | 1113 | Xid | 753306 | 1144 | COMMIT /* xid=1084 */ |
+------------------+------+-------------+-----------+-------------+----------------------------------------------------+
19 rows in set (0.00 sec)
mysql>show binlog events in 'mysql-bin.000004';
+------------------+------+-------------+-----------+-------------+----------------------------------------------------+
| Log_name | Pos | Event_type | Server_id | End_log_pos | Info |
+------------------+------+-------------+-----------+-------------+----------------------------------------------------+
| mysql-bin.000004 | 4 | Format_desc | 753306 | 120 | Server ver: 5.6.16-64.2-rel64.2-log, Binlog ver: 4 |
| mysql-bin.000004 | 120 | Query | 753306 | 209 | use `wubx`; truncate table tb_wubx |
| mysql-bin.000004 | 209 | Query | 753306 | 281 | BEGIN |
| mysql-bin.000004 | 281 | Table_map | 753306 | 334 | table_id: 91 (wubx.tb_wubx) |
| mysql-bin.000004 | 334 | Write_rows | 753306 | 393 | table_id: 91 flags: STMT_END_F |
| mysql-bin.000004 | 393 | Xid | 753306 | 424 | COMMIT /* xid=1073 */ |
| mysql-bin.000004 | 424 | Query | 753306 | 496 | BEGIN |
| mysql-bin.000004 | 496 | Table_map | 753306 | 549 | table_id: 91 (wubx.tb_wubx) |
| mysql-bin.000004 | 549 | Write_rows | 753306 | 602 | table_id: 91 flags: STMT_END_F |
| mysql-bin.000004 | 602 | Xid | 753306 | 633 | COMMIT /* xid=1074 */ |
| mysql-bin.000004 | 633 | Query | 753306 | 722 | use `wubx`; truncate table tb_wubx |
| mysql-bin.000004 | 722 | Query | 753306 | 794 | BEGIN |
| mysql-bin.000004 | 794 | Table_map | 753306 | 847 | table_id: 92 (wubx.tb_wubx) |
| mysql-bin.000004 | 847 | Write_rows | 753306 | 894 | table_id: 92 flags: STMT_END_F |
| mysql-bin.000004 | 894 | Xid | 753306 | 925 | COMMIT /* xid=1081 */ |
| mysql-bin.000004 | 925 | Query | 753306 | 997 | BEGIN |
| mysql-bin.000004 | 997 | Table_map | 753306 | 1050 | table_id: 92 (wubx.tb_wubx) |
| mysql-bin.000004 | 1050 | Update_rows | 753306 | 1113 | table_id: 92 flags: STMT_END_F |
| mysql-bin.000004 | 1113 | Xid | 753306 | 1144 | COMMIT /* xid=1084 */ |
+------------------+------+-------------+-----------+-------------+----------------------------------------------------+
19 rows in set (0.00 sec)
MYSQL学习看到这个表刚开始就发生一次truncate, 那其实也可以说明我就恢复刚开始那个truncate到后来那个误操作的truncate table的语句之间的数据就是丢失的数据.
这个恢复可以从mysql-bin.000004 pos: 4到mysql-bin.000004 pos: 633 即：
MYSQL学习
mysqlbinlog --rewrite-db='wubx->re_wubx' --start-position=4 --stop-position=633 mysql-bin.000004 |mysql -S /tmp/mysql.sock re_wubx
mysqlbinlog --rewrite-db='wubx->re_wubx' --start-position=4 --stop-position=633 mysql-bin.000004 |mysql -S /tmp/mysql.sock re_wubx
MYSQL学习恢复结果如下：
MYSQL学习
mysql -S /tmp/mysql.sock re_wubx;
mysql>select count(*) from tb_wubx;
+----------+
| count(*) |
+----------+
| 3 |
+----------+
1 row in set (0.02 sec)
mysql>select * from tb_wubx;
+----+--------------+
| id | name |
+----+--------------+
| 1 | 张三 |
| 2 | 李四 |
| 3 | 隔壁老王 |
+----+--------------+
3 rows in set (0.00 sec)
mysql>insert into tb_wubx(name) select name from wubx.tb_wubx;
Query OK, 1 row affected (0.00 sec)
Records: 1 Duplicates: 0 Warnings: 0
mysql> rename table wubx.tb_wubx to wubx.bak_tb_wubx;
Query OK, 0 rows affected (0.04 sec)
mysql> rename table re_wubx.tb_wubx to wubx.tb_wubx;
Query OK, 0 rows affected (0.03 sec)
mysql> select * from wubx.tb_wubx;
+----+--------------+
| id | name |
+----+--------------+
| 1 | 张三 |
| 2 | 李四 |
| 3 | 隔壁老王 |
| 4 | 老赵赵 |
+----+--------------+
4 rows in set (0.00 sec)
mysql -S /tmp/mysql.sock re_wubx;
mysql>select count(*) from tb_wubx;
+----------+
| count(*) |
+----------+
| 3 |
+----------+
1 row in set (0.02 sec)
mysql>select * from tb_wubx;
+----+--------------+
| id | name |
+----+--------------+
| 1 | 张三 |
| 2 | 李四 |
| 3 | 隔壁老王 |
+----+--------------+
3 rows in set (0.00 sec)
mysql>insert into tb_wubx(name) select name from wubx.tb_wubx;
Query OK, 1 row affected (0.00 sec)
Records: 1 Duplicates: 0 Warnings: 0
mysql> rename table wubx.tb_wubx to wubx.bak_tb_wubx;
Query OK, 0 rows affected (0.04 sec)
mysql> rename table re_wubx.tb_wubx to wubx.tb_wubx;
Query OK, 0 rows affected (0.03 sec)
mysql> select * from wubx.tb_wubx;
+----+--------------+
| id | name |
+----+--------------+
| 1 | 张三 |
| 2 | 李四 |
| 3 | 隔壁老王 |
| 4 | 老赵赵 |
+----+--------------+
4 rows in set (0.00 sec)
MYSQL学习恢复完成.
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