mysql如何从全备文件中恢复单个库或者单个表

时间:2021-07-02 14:45:56

mysql如何从全备文件中恢复单个库或者单个表

  在mysql dba的日常实际工作中,一个实例下有多个库,而我们常见的备份就是全库备份。那么问题就来了,如果需要恢复单个库或者单个表,怎么办了,网上有很多人都有多种方法,今天,我自己结合众多资料,将实践记录下来,以便供参考。
基本情况介绍:
mysql版本:mysql-5.5.36.tar.gz
操作系统:CentOS release 6.8 x64 (Final)

一、全库备份

[root@pre ~]# cat backup.sh
#!/bin/bash
/home/mysql/mysql55_3310/bin/mysqldump --defaults-file=/usr/local/local.cnf -E --triggers -e --max_allowed_packet=16777216 --net_buffer_length=16384 --master-data=2 --single-transaction --all-databases --quick | gzip >/home/dbbackup/all_database_bak_471_`date +%Y-%m-%d_%H_%M_%S`.sql.gz
[root@pre ~]# cat /usr/local/local.cnf
[client]
host=localhost
port=3310
user=root
password=123456
socket=/home/mysql/mysql55_3310/data/mysql.sock
[root@pre ~]# sh backup.sh

二、显示当前库

mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| db_log |
| db_users |
| mysql |
| performance_schema |
+--------------------+
5 rows in set (0.00 sec)
mysql> use db_log;
Database changed
mysql> show tables;
Empty set (0.00 sec)

三、现在从全备文件中恢复db_log单个库

# 从全备份文件中将需要的库的建表语句和INSERT数据拿出来,然后再导入
[root@pre ~]# sed -n '/^-- Current Database: `db_log`/,/^-- Current Database: `/p' all_database_bak_471_2017-12-04_15_36_38.sql > db_log.sql &
# 导入库中
[root@pre ~]# /home/mysql/mysql55_3310/bin/mysql -uroot -p < db_log.sql &
mysql> use db_log;
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> show tables;
+------------------------+
| Tables_in_db_log |
+------------------------+
| api_online_logs |
| onlinegame |
| onlinegame_gamestats |
| onlinegame_playerstats |
| onlinegame_type |
| osa_menu_url |
| osa_module |
| osa_quick_note |
| osa_sys_log |
| osa_system |
| osa_user |
| osa_user_group |
| sample |
| user_online |
| user_psw_audit |
+------------------------+
15 rows in set (0.00 sec) mysql> # 数据已经恢复了

四、现在模拟恢复单个表的数据

# 先删除一个表: user_online
mysql> drop table user_online;
Query OK, 0 rows affected (0.01 sec) # 1、从全备份中提取出该表的建表语句
[root@pre ~]# sed -e'/./{H;$!d;}' -e 'x;/CREATE TABLE `user_online`/!d;q' all_database_bak_471_2017-12-04_15_36_38.sql > user_online.sql & # 2、提取该表的insert into语句
[root@pre ~]# grep -i 'INSERT INTO `user_online`' all_database_bak_471_2017-12-04_15_36_38.sql >> user_online.sql & # 3、导入到对应的库中
[root@pre ~]# /home/mysql/mysql55_3310/bin/mysql -uroot -p <user_online.sql & # 4、查看数据
mysql> select count(*) from user_online;
+----------+
| count(*) |
+----------+
| 9 |
+----------+
1 row in set (0.01 sec) # 已经恢复完毕