binlog恢复误删的数据库

1 查看当前数据库内容并备份数据库

查看数据库信息：

备份数据库：

[root@localhost ~]# mysqldump -u root -p t > /mnt/t.sql
Enter password: 
[root@localhost ~]# ll /mnt/t.sql 
-rw-r--r-- 1 root root 1771 Aug 25 11:56 /mnt/t.sql

2 开启bin_log功能

首先查看数据库是否开启bin_log功能

mysql> show variables like "%log_bin%";

需要修改mysql的配置文件，/etc/的my.cnf，添加一句​​log_bin = mysql_bin​​即可

3 模拟误操作（插入3条数据，删除数据库）

mysql> insert into t1 values (3);
Query OK, 1 row affected (0.00 sec)

mysql> insert into t1 values (4);
Query OK, 1 row affected (0.00 sec)

mysql> insert into t1 values (5);
Query OK, 1 row affected (0.00 sec)

mysql> select * from t1;
+------+
| id   |
+------+
|    1 |
|    2 |
|    5 |
|    4 |
|    3 |
+------+
5 rows in set (0.00 sec)

mysql> flush logs;
Query OK, 0 rows affected (0.00 sec)

mysql> show master status;
+------------------+----------+--------------+------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+------------------+
| mysql_bin.000003 |      106 |              |                  |
+------------------+----------+--------------+------------------+
1 row in set (0.00 sec)

删除数据：

mysql> truncate t1;
Query OK, 0 rows affected (0.00 sec)

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

此时突然数据库损坏或者人为删除

mysql> drop table t1;
Query OK, 0 rows affected (0.00 sec)

mysql> show tables;
Empty set (0.00 sec)

4 数据恢复

1 用已经备份的/mnt/t.sql来恢复数据

mysql> source /mnt/t.sql;
Query OK, 0 rows affected (0.00 sec)

Query OK, 0 rows affected (0.00 sec)

Query OK, 0 rows affected (0.00 sec)

Query OK, 0 rows affected (0.00 sec)

Query OK, 0 rows affected (0.00 sec)

Query OK, 0 rows affected (0.00 sec)

Query OK, 0 rows affected (0.00 sec)

Query OK, 0 rows affected (0.00 sec)

Query OK, 0 rows affected (0.00 sec)

Query OK, 0 rows affected (0.00 sec)

Query OK, 0 rows affected (0.00 sec)

Query OK, 0 rows affected (0.00 sec)

Query OK, 0 rows affected (0.00 sec)

Query OK, 0 rows affected (0.01 sec)

Query OK, 0 rows affected (0.00 sec)

Query OK, 0 rows affected (0.00 sec)

Query OK, 0 rows affected (0.00 sec)

Query OK, 2 rows affected (0.00 sec)
Records: 2  Duplicates: 0  Warnings: 0

Query OK, 0 rows affected (0.00 sec)

Query OK, 0 rows affected (0.00 sec)

Query OK, 0 rows affected (0.00 sec)

Query OK, 0 rows affected (0.00 sec)

Query OK, 0 rows affected (0.00 sec)

Query OK, 0 rows affected (0.00 sec)

Query OK, 0 rows affected (0.00 sec)

Query OK, 0 rows affected (0.00 sec)

Query OK, 0 rows affected (0.00 sec)

Query OK, 0 rows affected (0.00 sec)
mysql> show tables;
+-------------+
| Tables_in_t |
+-------------+
| t1          |
+-------------+
1 row in set (0.00 sec)

mysql> select * from t1;
+------+
| id   |
+------+
|    1 |
|    2 |
+------+
2 rows in set (0.00 sec)

2 还有三条数据没有恢复，怎么办。只能用bin-log来恢复

[root@localhost ~]# mysqlbinlog --no-defaults /var/lib/mysql/mysql_bin.000002 | mysql -u root -p123.com t

mysql> use t;
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> select * from t1;
+------+
| id   |
+------+
|    1 |
|    2 |
|    3 |
|    4 |
|    5 |
+------+
5 rows in set (0.00 sec)

mysql>

5 总结

备份数据

mysqldump -uroot -p123456 test -l -F '/tmp/test.sql'
-l:读锁（只能读取，不能更新）
-F:即flush logs，可以重新生成新的日志文件，当然包括log-bin日志

查看binlog日志

mysql>show master status;

导入之前备份数据

mysql -uroot -p t -v -f </mnt/t.sql
-v查看导入的详细信息
-f是当中间遇到错误时，可以skip过去，继续执行下面的语句

恢复binlog-file二进制日志文件

mysqlbinlog --no-defaults binlog-file | mysql -uroot -p t

从某一(367)点开始恢复

mysqlbinlog --no-defaults --stop-position="367" mysql-bin.000001| mysql -uroot -p t

先查好那一点，用more来查看

[root@localhost mysql]# /usr/bin/mysqlbinlog --no-defaults mysql-bin.000002 --start-position="794" --stop-position="1055" | more

然后恢复

[root@localhost mysql]# /usr/bin/mysqlbinlog --no-defaults mysql-bin.000002 --start-position="794" --stop-position="1055" | /usr/bin/mysql -uroot -p t

重置binlog日志

mysql> reset master;
Query OK, 0 rows affected (0.01 sec)

mysql> show master status;
+------------------+----------+--------------+------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+------------------+
| mysql-bin.000001 |      106 |              |                  |
+------------------+----------+--------------+------------------+

mysql> flush logs;#关闭当前的二进制日志文件并创建一个新文件，新的二进制日志文件的名字在当前的二进制文件的编号上加1。