zoukankan html css js c++ java

MySQL 误操作后数据恢复（update,delete忘加where条件）

在数据库日常维护中，开发人员是最让人头痛的，很多时候都会由于SQL语句写的有问题导致服务器出问题，导致资源耗尽。最危险的操作就是在做DML操作的时候忘加where条件，导致全表更新，这是作为运维或者DBA的我们改如何处理呢？下面我分别针对update和delete操作忘加where条件导致全表更新的处理方法。

一. update 忘加where条件误操作恢复数据(binglog格式必须是ROW)

1.创建测试用的数据表

mysql> create table t1 (
    -> id int unsigned not null auto_increment,
    -> name char(20) not null,
    -> sex enum('f','m') not null default 'm',
    -> address varchar(30) not null,
    -> primary key(id)
    -> );
Query OK, 0 rows affected (0.31 sec)

mysql>

2.插入测试数据

mysql> insert into t1 (name,sex,address)values('daiiy','m','guangzhou');
Query OK, 1 row affected (0.01 sec)

mysql> insert into t1 (name,sex,address)values('tom','f','shanghai');   
Query OK, 1 row affected (0.00 sec)

mysql> insert into t1 (name,sex,address)values('liany','m','beijing'); 
Query OK, 1 row affected (0.00 sec)

mysql> insert into t1 (name,sex,address)values('lilu','m','zhuhai');  
Query OK, 1 row affected (0.05 sec)

mysql>

3.现在需要将id等于2的用户的地址改为zhuhai，update时没有添加where条件

mysql> select * from t1;
+----+-------+-----+-----------+
| id | name  | sex | address   |
+----+-------+-----+-----------+
|  1 | daiiy | m   | guangzhou |
|  2 | tom   | f   | shanghai  |
|  3 | liany | m   | beijing   |
|  4 | lilu  | m   | zhuhai    |
+----+-------+-----+-----------+
4 rows in set (0.01 sec)

mysql> update t1 set address='zhuhai';
Query OK, 3 rows affected (0.09 sec)
Rows matched: 4  Changed: 3  Warnings: 0

mysql> select * from t1;              
+----+-------+-----+---------+
| id | name  | sex | address |
+----+-------+-----+---------+
|  1 | daiiy | m   | zhuhai  |
|  2 | tom   | f   | zhuhai  |
|  3 | liany | m   | zhuhai  |
|  4 | lilu  | m   | zhuhai  |
+----+-------+-----+---------+
4 rows in set (0.00 sec)

mysql>

4.开始恢复，在线上的话，应该比较复杂，要先进行锁表，以免数据再次被污染。（锁表，查看正在写哪个二进制日志）

mysql> lock tables t1 read ;
Query OK, 0 rows affected (0.00 sec)

mysql> show master status;
+------------------+----------+--------------+------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+------------------+
| mysql-bin.000024 |     1852 |              |                  |
+------------------+----------+--------------+------------------+
1 row in set (0.00 sec)

mysql>

5.分析二进制日志，并且在其中找到相关记录，在更新时是address='zhuhai',我们可以在日志中过滤出来。

[root@localhost mysql]# mysqlbinlog --no-defaults -v -v --base64-output=DECODE-ROWS mysql-bin.000024 | grep -B 15 'zhuhai'

# at 1629
# at 1679
#140305 10:52:24 server id 1  end_log_pos 1679  Table_map: `db01`.`t1` mapped to number 38
#140305 10:52:24 server id 1  end_log_pos 1825  Update_rows: table id 38 flags: STMT_END_F
### UPDATE db01.t1
### WHERE
###   @1=1 /* INT meta=0 nullable=0 is_null=0 */
###   @2='daiiy' /* STRING(60) meta=65084 nullable=0 is_null=0 */
###   @3=2 /* ENUM(1 byte) meta=63233 nullable=0 is_null=0 */
###   @4='guangzhou' /* VARSTRING(90) meta=90 nullable=0 is_null=0 */
### SET
###   @1=1 /* INT meta=0 nullable=0 is_null=0 */
###   @2='daiiy' /* STRING(60) meta=65084 nullable=0 is_null=0 */
###   @3=2 /* ENUM(1 byte) meta=63233 nullable=0 is_null=0 */
###   @4='zhuhai' /* VARSTRING(90) meta=90 nullable=0 is_null=0 */
### UPDATE db01.t1
### WHERE
###   @1=2 /* INT meta=0 nullable=0 is_null=0 */
###   @2='tom' /* STRING(60) meta=65084 nullable=0 is_null=0 */
###   @3=1 /* ENUM(1 byte) meta=63233 nullable=0 is_null=0 */
###   @4='shanghai' /* VARSTRING(90) meta=90 nullable=0 is_null=0 */
### SET
###   @1=2 /* INT meta=0 nullable=0 is_null=0 */
###   @2='tom' /* STRING(60) meta=65084 nullable=0 is_null=0 */
###   @3=1 /* ENUM(1 byte) meta=63233 nullable=0 is_null=0 */
###   @4='zhuhai' /* VARSTRING(90) meta=90 nullable=0 is_null=0 */
### UPDATE db01.t1
### WHERE
###   @1=3 /* INT meta=0 nullable=0 is_null=0 */
###   @2='liany' /* STRING(60) meta=65084 nullable=0 is_null=0 */
###   @3=2 /* ENUM(1 byte) meta=63233 nullable=0 is_null=0 */
###   @4='beijing' /* VARSTRING(90) meta=90 nullable=0 is_null=0 */
### SET
###   @1=3 /* INT meta=0 nullable=0 is_null=0 */
###   @2='liany' /* STRING(60) meta=65084 nullable=0 is_null=0 */
###   @3=2 /* ENUM(1 byte) meta=63233 nullable=0 is_null=0 */
###   @4='zhuhai' /* VARSTRING(90) meta=90 nullable=0 is_null=0 */

可以看见里面记录了每一行的变化，这也是binglog格式要一定是row才行的原因。其中@1,@2,@3,@4,分别对应表中id,name,sex,address字段。相信大家看到这里有点明白了吧，对，没错，你猜到了，我们将相关记录转换为sql语句，重新导入数据库。

6.处理分析处理的二进制日志

[root@localhost mysql]# mysqlbinlog --no-defaults -v -v --base64-output=DECODE-ROWS mysql-bin.000024 | sed -n '/# at 1679/,/COMMIT/p' > t1.txt  
[root@localhost mysql]# cat t1.txt 
# at 1679
#140305 10:52:24 server id 1  end_log_pos 1679  Table_map: `db01`.`t1` mapped to number 38
#140305 10:52:24 server id 1  end_log_pos 1825  Update_rows: table id 38 flags: STMT_END_F
### UPDATE db01.t1
### WHERE
###   @1=1 /* INT meta=0 nullable=0 is_null=0 */
###   @2='daiiy' /* STRING(60) meta=65084 nullable=0 is_null=0 */
###   @3=2 /* ENUM(1 byte) meta=63233 nullable=0 is_null=0 */
###   @4='guangzhou' /* VARSTRING(90) meta=90 nullable=0 is_null=0 */
### SET
###   @1=1 /* INT meta=0 nullable=0 is_null=0 */
###   @2='daiiy' /* STRING(60) meta=65084 nullable=0 is_null=0 */
###   @3=2 /* ENUM(1 byte) meta=63233 nullable=0 is_null=0 */
###   @4='zhuhai' /* VARSTRING(90) meta=90 nullable=0 is_null=0 */
### UPDATE db01.t1
### WHERE
###   @1=2 /* INT meta=0 nullable=0 is_null=0 */
###   @2='tom' /* STRING(60) meta=65084 nullable=0 is_null=0 */
###   @3=1 /* ENUM(1 byte) meta=63233 nullable=0 is_null=0 */
###   @4='shanghai' /* VARSTRING(90) meta=90 nullable=0 is_null=0 */
### SET
###   @1=2 /* INT meta=0 nullable=0 is_null=0 */
###   @2='tom' /* STRING(60) meta=65084 nullable=0 is_null=0 */
###   @3=1 /* ENUM(1 byte) meta=63233 nullable=0 is_null=0 */
###   @4='zhuhai' /* VARSTRING(90) meta=90 nullable=0 is_null=0 */
### UPDATE db01.t1
### WHERE
###   @1=3 /* INT meta=0 nullable=0 is_null=0 */
###   @2='liany' /* STRING(60) meta=65084 nullable=0 is_null=0 */
###   @3=2 /* ENUM(1 byte) meta=63233 nullable=0 is_null=0 */
###   @4='beijing' /* VARSTRING(90) meta=90 nullable=0 is_null=0 */
### SET
###   @1=3 /* INT meta=0 nullable=0 is_null=0 */
###   @2='liany' /* STRING(60) meta=65084 nullable=0 is_null=0 */
###   @3=2 /* ENUM(1 byte) meta=63233 nullable=0 is_null=0 */
###   @4='zhuhai' /* VARSTRING(90) meta=90 nullable=0 is_null=0 */
# at 1825
#140305 10:52:24 server id 1  end_log_pos 1852  Xid = 26
COMMIT/*!*/;
[root@localhost mysql]#

这里sed有点复杂，需要童鞋们好好自己研究研究，这里我就不多说了。

[root@localhost mysql]# sed '/WHERE/{:a;N;/SET/!ba;s/([^
]*)
(.*)
(.*)/3
2
1/}' t1.txt | sed -r '/WHERE/{:a;N;/@4/!ba;s/###   @2.*//g}' | sed 's/### //g;s//*.*/,/g' | sed '/WHERE/{:a;N;/@1/!ba;s/,/;/g};s/#.*//g;s/COMMIT,//g' | sed '/^$/d' > recover.sql

[root@localhost mysql]# cat recover.sql 
UPDATE db01.t1
SET
  @1=1 ,
  @2='daiiy' ,
  @3=2 ,
  @4='guangzhou' ,
WHERE
  @1=1 ;
UPDATE db01.t1
SET
  @1=2 ,
  @2='tom' ,
  @3=1 ,
  @4='shanghai' ,
WHERE
  @1=2 ;
UPDATE db01.t1
SET
  @1=3 ,
  @2='liany' ,
  @3=2 ,
  @4='beijing' ,
WHERE
  @1=3 ;
[root@localhost mysql]#

将文件中的@1,@2,@3,@4替换为t1表中id，name，sex，address字段，并删除最后字段的","号

[root@localhost mysql]# sed -i 's/@1/id/g;s/@2/name/g;s/@3/sex/g;s/@4/address/g' recover.sql
[root@localhost mysql]# sed -i -r 's/(address=.*),/1/g' recover.sql
[root@localhost mysql]# cat recover.sql 
UPDATE db01.t1
SET
  id=1 ,
  name='daiiy' ,
  sex=2 ,
  address='guangzhou' 
WHERE
  id=1 ;
UPDATE db01.t1
SET
  id=2 ,
  name='tom' ,
  sex=1 ,
  address='shanghai' 
WHERE
  id=2 ;
UPDATE db01.t1
SET
  id=3 ,
  name='liany' ,
  sex=2 ,
  address='beijing' 
WHERE
  id=3 ;
[root@localhost mysql]#

7.到这里日志就处理好了，现在导入即可（导入数据后，解锁表）；

mysql> source recover.sql;
Query OK, 1 row affected (0.12 sec)
Rows matched: 1  Changed: 1  Warnings: 0

Query OK, 1 row affected (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 0

Query OK, 1 row affected (0.01 sec)
Rows matched: 1  Changed: 1  Warnings: 0

mysql> select * from t1;
+----+-------+-----+-----------+
| id | name  | sex | address   |
+----+-------+-----+-----------+
|  1 | daiiy | m   | guangzhou |
|  2 | tom   | f   | shanghai  |
|  3 | liany | m   | beijing   |
|  4 | lilu  | m   | zhuhai    |
+----+-------+-----+-----------+
4 rows in set (0.00 sec)

mysql>

可以看见数据已经完全恢复，这种方法的优点是快速，方便。

二. delete 忘加where条件误删除恢复(binglog格式必须是ROW)

其实这和update忘加条件差不多，不过这处理更简单,这里就用上面那张表做测试吧

1.模拟误删除数据

mysql> select * from t1;
+----+-------+-----+-----------+
| id | name  | sex | address   |
+----+-------+-----+-----------+
|  1 | daiiy | m   | guangzhou |
|  2 | tom   | f   | shanghai  |
|  3 | liany | m   | beijing   |
|  4 | lilu  | m   | zhuhai    |
+----+-------+-----+-----------+
4 rows in set (0.00 sec)

mysql> delete from t1;
Query OK, 4 rows affected (0.03 sec)

mysql> select * from t1;
Empty set (0.00 sec)

mysql>

2.在binglog中去查找相关记录

[root@localhost mysql]# mysqlbinlog --no-defaults --base64-output=decode-rows -v -v mysql-bin.000024 | sed -n '/### DELETE FROM db01.t1/,/COMMIT/p' > delete.txt
[root@localhost mysql]# cat delete.txt 
### DELETE FROM db01.t1
### WHERE
###   @1=1 /* INT meta=0 nullable=0 is_null=0 */
###   @2='daiiy' /* STRING(60) meta=65084 nullable=0 is_null=0 */
###   @3=2 /* ENUM(1 byte) meta=63233 nullable=0 is_null=0 */
###   @4='guangzhou' /* VARSTRING(90) meta=90 nullable=0 is_null=0 */
### DELETE FROM db01.t1
### WHERE
###   @1=2 /* INT meta=0 nullable=0 is_null=0 */
###   @2='tom' /* STRING(60) meta=65084 nullable=0 is_null=0 */
###   @3=1 /* ENUM(1 byte) meta=63233 nullable=0 is_null=0 */
###   @4='shanghai' /* VARSTRING(90) meta=90 nullable=0 is_null=0 */
### DELETE FROM db01.t1
### WHERE
###   @1=3 /* INT meta=0 nullable=0 is_null=0 */
###   @2='liany' /* STRING(60) meta=65084 nullable=0 is_null=0 */
###   @3=2 /* ENUM(1 byte) meta=63233 nullable=0 is_null=0 */
###   @4='beijing' /* VARSTRING(90) meta=90 nullable=0 is_null=0 */
### DELETE FROM db01.t1
### WHERE
###   @1=4 /* INT meta=0 nullable=0 is_null=0 */
###   @2='lilu' /* STRING(60) meta=65084 nullable=0 is_null=0 */
###   @3=2 /* ENUM(1 byte) meta=63233 nullable=0 is_null=0 */
###   @4='zhuhai' /* VARSTRING(90) meta=90 nullable=0 is_null=0 */
# at 2719
#140305 11:41:00 server id 1  end_log_pos 2746  Xid = 78
COMMIT/*!*/;
[root@localhost mysql]#

3.将记录转换为SQL语句

[root@localhost mysql]# cat delete.txt | sed -n '/###/p' | sed 's/### //g;s//*.*/,/g;s/DELETE FROM/INSERT INTO/g;s/WHERE/SELECT/g;' | sed -r 's/(@4.*),/1;/g' | sed 's/@[1-9]=//g' > t1.sql
[root@localhost mysql]# cat t1.sql 
INSERT INTO db01.t1
SELECT
  1 ,
  'daiiy' ,
  2 ,
  'guangzhou' ;
INSERT INTO db01.t1
SELECT
  2 ,
  'tom' ,
  1 ,
  'shanghai' ;
INSERT INTO db01.t1
SELECT
  3 ,
  'liany' ,
  2 ,
  'beijing' ;
INSERT INTO db01.t1
SELECT
  4 ,
  'lilu' ,
  2 ,
  'zhuhai' ;
[root@localhost mysql]#

4.导入数据，验证数据完整性

mysql> source t1.sql;
Query OK, 1 row affected (0.00 sec)
Records: 1  Duplicates: 0  Warnings: 0

Query OK, 1 row affected (0.02 sec)
Records: 1  Duplicates: 0  Warnings: 0

Query OK, 1 row affected (0.02 sec)
Records: 1  Duplicates: 0  Warnings: 0

Query OK, 1 row affected (0.01 sec)
Records: 1  Duplicates: 0  Warnings: 0

mysql> select * from t1;
ERROR 1046 (3D000): No database selected
mysql> select * from db01.t1;
+----+-------+-----+-----------+
| id | name  | sex | address   |
+----+-------+-----+-----------+
|  1 | daiiy | m   | guangzhou |
|  2 | tom   | f   | shanghai  |
|  3 | liany | m   | beijing   |
|  4 | lilu  | m   | zhuhai    |
+----+-------+-----+-----------+
4 rows in set (0.00 sec)

mysql>

到这里数据就完整回来了。将binglog格式设置为row有利有弊，好处是记录了每一行的实际变化，在主从复制时也不容易出问题。但是由于记录每行的变化，会占用大量磁盘，主从复制时带宽占用会有所消耗。到底是使用row还是mixed，需要在实际工作中自己去衡量，但从整体上来说，binglog的格式设置为row，都是不二的选择。

总结：

所以在数据库操作的过程中我们需要格外小心，当然开发那边我们需要做好权限的控制，不过有一个参数可以解决我们的问题，让我们不用担心类似的问题发生：

在[mysql]段落开启这个参数：

safe-updates

这样当我们在做DML操作时忘记加where条件时，mysqld服务器是不会执行操作的：

mysql> select *  from t1;
+----+------------------+
| id | name             |
+----+------------------+
|  1 | yayun            |
|  2 | atlas            |
|  3 | mysql            |
|  6 | good yayun heheh |
+----+------------------+
4 rows in set (0.00 sec)

mysql> delete from t1;
ERROR 1175 (HY000): You are using safe update mode and you tried to update a table without a WHERE that uses a KEY column
mysql>

查看全文

相关阅读:
单例模式
 HashSet、LinkedHashSet、SortedSet、TreeSet
ArrayList、LinkedList、CopyOnWriteArrayList
HashMap、Hashtable、LinkedHashMap
andrew ng machine learning week8 非监督学习
 andrew ng machine learning week7 支持向量机
 andrew ng machine learning week6 机器学习算法理论
 andrew ng machine learning week5 神经网络
 andrew ng machine learning week4 神经网络
 vue组件监听属性变化watch方法报[Vue warn]: Method "watch" has type "object" in the component definition. Did you reference the function correctly?

原文地址：https://www.cnblogs.com/gomysql/p/3582058.html

最新文章
HDU 1796 容斥原理
 POJ 2773 欧几里得
 HDU 5514 欧拉函数应用
 POJ 2194 2850 计算几何
 POJ 3608 旋转卡壳
 POJ
POJ
POJ
POJ
PTA 7-2 深入虎穴（30 分)