mysql5.7.33誤刪除ibdata文件找回數據

1、場景說明：

不少時候由於 MySQL 數據庫不能啓動而形成數據沒法訪問，但應用的數據一般沒有丟失，只是系統表空間等其它文件損壞了，或者遇到 MySQL 的 bug。
這個時候若是沒有備份，不少人就覺得數據丟失了，但實際上大部分時候數據仍是有救的。
對於 MyISAM 引擎的表空間，直接把對應的數據文件拷貝到一個新的數據庫就好了，數據就能夠恢復了。
對於 InnoDB 引擎的數據庫表空間能夠採用傳輸表空間的方式把數據救回來.
前提是MySQL開啓了參數 innodb_file_per_table = 1 獨立表空間文件

當MySQL的數據表空間文件ibdata文件損壞或者是被無修改和刪除，致使MySQL服務重啓失敗。同時MySQL的數據又沒有及時備份，此時如何儘量多的找回MySQL數據呢？？

2、案例演示：

2.一、確認MySQL故障前，庫中的每張表有多少記錄

for n in `mysql -e "use  db_bbs;show tables;"|sed '1d'`;do echo $n; mysql -e "use  db_bbs;select count(*) from $n;";done >test.txt

確認MySQL故障前，庫中一共有多少張表：

一共是39張表：
[root@10-10-127-11 ~]# mysql -e "use db_bbs;show tables;"|sed '1d'|wc -l
39

2.二、模擬刪除ibdata故障：

刪除ibdata文件（生產環境禁止這麼幹）

innodb_force_recovery =6 利用MySQL的強制啓動參數來啓動此時的MySQL服務，可是已是無濟於事。因爲是數據表空間文件ibdata文件被刪除了.因此啓動不了此時的MySQL服務。
因爲此MySQL採用的innodb引擎。並且開啓了獨立表空間參數 innodb_file_per_table = 1 。因此此時能夠採用採用傳輸表空間的方式把數據救回來。

2.三、找回數據的辦法:

首先來建立已經丟失的表結構：

先要在故障的MySQL服務器上 安裝 mysql-utilities。
yum -y install mysql-utilities
使用 mysqlfrm 從 .frm 文件裏面找回建表語句:

分析一個 .frm 文件生成建表的語句

mysqlfrm --diagnostic  
[root@test02 db_bbs]# mysqlfrm --diagnostic /data/mysql/data/db_bbs/t_admin.frm  |grep -v "^#"
CREATE TABLE `db_bbs`.`t_admin` (
  `f_id` int(4) NOT NULL AUTO_INCREMENT, 
  `f_type` tinyint(1) NOT NULL, 
  `f_username` varchar(80) NOT NULL, 
  `f_password` varchar(80) NOT NULL, 
  `f_nick_name` varchar(80) NOT NULL, 
  `f_real_name` varchar(80) NOT NULL, 
  `f_create_time` bigint(4) NOT NULL, 
  `f_update_time` bigint(4) NOT NULL, 
  `f_last_login_time` bigint(4) DEFAULT NULL, 
  `f_last_login_ip` varchar(80) DEFAULT NULL, 
  `f_status` tinyint(1) NOT NULL, 
PRIMARY KEY `PRIMARY` (`f_id`) USING BTREE
) ENGINE=InnoDB ROW_FORMAT = 2;

把所有的建表語句導入到/tmp/create.sql 文件：

[root@test02 ~]# cd /data/mysql/data/db_bbs/
[root@test02 db_bbs]# for n in `ls -l  /data/mysql/data/db_bbs/*.frm|awk -F '/' '{print $NF}'|xargs -n 40`;do mysqlfrm --diagnostic $n|grep -v "^#" >>/tmp/create.sql;done

把生產的建表語句導入到新MySQL實例庫中:

[root@10-10-127-11 ~]# mysql db_bbs < create.sql 
ERROR 1064 (42000) at line 2: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '5' at line 10
緣由是獲取到的建表sql中包含了ROW_FORMAT = 2 這樣的參數致使的

###去掉建表語句中的包含ROW_FORMAT = 2, ROW_FORMAT = 5這些字符.從新導入建表語句###

批量替換命令以下:

cat /tmp/create.sql|sed -e 's/ENGINE=InnoDB ROW_FORMAT = 2;/ENGINE=InnoDB ;/g'|grep ROW_FORMAT |uniq -c
cat /tmp/create.sql|sed -e 's/ENGINE=InnoDB ROW_FORMAT = 5;/ENGINE=InnoDB ;/g'|grep ROW_FORMAT |uniq -c
sed -i 's/ENGINE=InnoDB ROW_FORMAT = 2;/ENGINE=InnoDB ;/g' /tmp/create.sql
sed -i 's/ENGINE=InnoDB ROW_FORMAT = 5;/ENGINE=InnoDB ;/g' /tmp/create.sql
cat /tmp/create.sql|grep ROW_FORMAT |uniq -c

導出建表語句到新MySQL實例db_bbs庫報錯字段太長：

[root@10-10-127-11 ~]# mysql db_bbs -f < create.sql 
ERROR 1074 (42000) at line 232: Column length too big for column 'f_content' (max = 16383); use BLOB or TEXT instead
ERROR 1074 (42000) at line 299: Column length too big for column 'f_desc' (max = 16383); use BLOB or TEXT instead
ERROR 1074 (42000) at line 365: Column length too big for column 'f_body_image' (max = 16383); use BLOB or TEXT instead
ERROR 1074 (42000) at line 406: Column length too big for column 'f_content' (max = 16383); use BLOB or TEXT instead
ERROR 1074 (42000) at line 433: Column length too big for column 'f_summary' (max = 16383); use BLOB or TEXT instead

修改完字段長度類型，從新導入建表sql到全新的MySQL庫中

[root@10-10-127-11 ~]# mysql db_bbs -f < create.sql  
[root@10-10-127-11 ~]# 
[root@10-10-127-11 ~]# 
[root@10-10-127-11 ~]# mysql -e "use db_bbs;show tables;"|sed '1d'|wc -l
39

###將新建的MySQL實例的 沒有包括數據的 .ibd 文件拋棄掉，而後再導入故障數據庫的.idb文件###

拋棄掉新建庫的數據.ibd文件：

mysql -e "show tables from db_bbs" | grep -v  Tables_in_db_bbs| while read a; do mysql -e  "ALTER TABLE db_bbs.$a DISCARD TABLESPACE" ;done

[root@10-10-127-11 db_bbs]# ll *.ibd|wc -l
39
[root@10-10-127-11 db_bbs]# mysql -e "show tables from db_bbs" | grep -v  Tables_in_db_bbs| while read a; do mysql -e  "ALTER TABLE db_bbs.$a DISCARD TABLESPACE" ;done
[root@10-10-127-11 db_bbs]# ll *.ibd|wc -l
ls: cannot access *.ibd: No such file or directory

0

*能夠看到全部的 .idb 文件都已經被拋棄了。而後把舊的有數據的 .ibd 文件拷貝到這個新MySQL實例的 ./data/db_bbs/ 目錄下面，別忘了把屬主改過來：chown mysql. ，再把這些數據文件 import 到數據庫中**。

[root@test02 db_bbs]# scp *.ibd root@10.10.127.11:/data/mysql/data/db_bbs/
root@10.10.127.11's password: 
browse_record.ibd                                                                                                                        100%  100MB  50.0MB/s   00:02    
t_admin.ibd                  
........
........

[root@10-10-127-11 db_bbs]# ll *.ibd|wc -l
39
[root@10-10-127-11 db_bbs]# ll *.ibd
-rw-r----- 1 root root 104857600 Mar 14 21:56 browse_record.ibd
-rw-r----- 1 root root     98304 Mar 14 21:56 t_admin.ibd
-rw-r----- 1 root root     98304 Mar 14 21:56 t_anonymous_code.ibd
-rw-r----- 1 root root     98304 Mar 14 21:56 t_apply.ibd
-rw-r----- 1 root root   9437184 Mar 14 21:56 t_attach.ibd
-rw-r----- 1 root root    147456 Mar 14 21:56 t_banner.ibd
-rw-r----- 1 root root    163840 Mar 14 21:56 t_banner_log.ibd
-rw-r----- 1 root root    114688 Mar 14 21:56 t_black_ip.ibd
-rw-r----- 1 root root     98304 Mar 14 21:56 t_black_user.ibd
-rw-r----- 1 root root     98304 Mar 14 21:56 t_block_userbaseinfo.ibd
-rw-r----- 1 root root     98304 Mar 14 21:56 t_collect.ibd
-rw-r----- 1 root root     98304 Mar 14 21:56 t_country_code.ibd
-rw-r----- 1 root root    163840 Mar 14 21:56 t_ct_goods.ibd
-rw-r----- 1 root root    131072 Mar 14 21:56 t_ct_goods_record.ibd
-rw-r----- 1 root root   9437184 Mar 14 21:56 t_ct_integral.ibd
-rw-r----- 1 root root  46137344 Mar 14 21:56 t_ct_integral_record.ibd
-rw-r----- 1 root root  27262976 Mar 14 21:56 t_ct_news.ibd
-rw-r----- 1 root root   9437184 Mar 14 21:56 t_ct_order.ibd
-rw-r----- 1 root root     98304 Mar 14 21:56 t_feedback.ibd
-rw-r----- 1 root root     98304 Mar 14 21:56 t_lexicon.ibd
-rw-r----- 1 root root    327680 Mar 14 21:56 t_logs.ibd
-rw-r----- 1 root root     98304 Mar 14 21:56 t_manage.ibd
-rw-r----- 1 root root     98304 Mar 14 21:56 t_module.ibd
-rw-r----- 1 root root   9437184 Mar 14 21:56 t_post_extend.ibd
-rw-r----- 1 root root  12582912 Mar 14 21:56 t_post.ibd
-rw-r----- 1 root root     98304 Mar 14 21:56 t_post_video.ibd
-rw-r----- 1 root root     98304 Mar 14 21:56 t_realtime_message.ibd
-rw-r----- 1 root root     98304 Mar 14 21:56 t_recommend.ibd
-rw-r----- 1 root root  46137344 Mar 14 21:56 t_reply.ibd
-rw-r----- 1 root root     98304 Mar 14 21:56 t_reward.ibd
-rw-r----- 1 root root    196608 Mar 14 21:56 t_sensitive_word.ibd
-rw-r----- 1 root root     98304 Mar 14 21:56 t_system_message.ibd
-rw-r----- 1 root root   9437184 Mar 14 21:56 t_userbaseinfo.ibd
-rw-r----- 1 root root    344064 Mar 14 21:56 t_userextendinfo.ibd
-rw-r----- 1 root root  12582912 Mar 14 21:56 t_user_health.ibd
-rw-r----- 1 root root     98304 Mar 14 21:56 t_user_message.ibd
-rw-r----- 1 root root    442368 Mar 14 21:56 t_user_read_module_log.ibd
-rw-r----- 1 root root  17825792 Mar 14 21:56 t_viewpoint.ibd
-rw-r----- 1 root root    114688 Mar 14 21:56 t_white_ip.ibd

[root@10-10-127-11 db_bbs]# chown mysql.mysql *.ibd

mysql -e "show tables from db_bbs" | grep -v  Tables_in_db_bbs| while read a; do mysql -e  "ALTER TABLE db_bbs.$a import TABLESPACE" ;done

導入每一個表的表空間時，出現個別表報錯：

[root@10-10-127-11 db_bbs]# mysql -e "show tables from db_bbs" | grep -v  Tables_in_db_bbs| while read a; do mysql -e  "ALTER TABLE db_bbs.$a import TABLESPACE" ;done 
ERROR 1808 (HY000) at line 1: Schema mismatch (Table has ROW_TYPE_DYNAMIC row format, .ibd file has ROW_TYPE_COMPACT row format.)

校驗表文件，發現只有browse_record表導入獨立表表空間時報錯致使此表恢復數據失敗

[root@10-10-127-11 db_bbs]# mysqlcheck -c db_bbs
db_bbs.browse_record
Warning  : InnoDB: Tablespace has been discarded for table 'browse_record'
Error    : Tablespace has been discarded for table 'browse_record'
error    : Corrupt
db_bbs.t_admin                                     OK
db_bbs.t_anonymous_code                            OK
db_bbs.t_apply                                     OK
db_bbs.t_attach                                    OK
db_bbs.t_banner                                    OK
db_bbs.t_banner_log                                OK
db_bbs.t_black_ip                                  OK
db_bbs.t_black_user                                OK
db_bbs.t_block_userbaseinfo                        OK
db_bbs.t_collect                                   OK
db_bbs.t_country_code                              OK
db_bbs.t_ct_goods                                  OK
db_bbs.t_ct_goods_record                           OK
db_bbs.t_ct_integral                               OK
db_bbs.t_ct_integral_record                        OK
db_bbs.t_ct_news                                   OK
db_bbs.t_ct_order                                  OK
db_bbs.t_feedback                                  OK
db_bbs.t_lexicon                                   OK
db_bbs.t_logs                                      OK
db_bbs.t_manage                                    OK
db_bbs.t_module                                    OK
db_bbs.t_post                                      OK
db_bbs.t_post_extend                               OK
db_bbs.t_post_video                                OK
db_bbs.t_realtime_message                          OK
db_bbs.t_recommend                                 OK
db_bbs.t_reply                                     OK
db_bbs.t_reward                                    OK
db_bbs.t_sensitive_word                            OK
db_bbs.t_system_message                            OK
db_bbs.t_user_health                               OK
db_bbs.t_user_message                              OK
db_bbs.t_user_read_module_log                      OK
db_bbs.t_userbaseinfo                              OK
db_bbs.t_userextendinfo                            OK
db_bbs.t_viewpoint                                 OK
db_bbs.t_white_ip                                  OK

上面的browse_record 表恢復失敗 報錯解決辦法以下：
參考：https://blog.csdn.net/weixin_30607659/article/details/94987901

刪除導入到新MySQL實例的表browse_record，而後執行下面的建表語句，新建browse_record表：

CREATE TABLE `browse_record` (
  `id` int(4) unsigned NOT NULL AUTO_INCREMENT,
  `post_id` int(4) unsigned NOT NULL,
  `user_id` int(4) unsigned NOT NULL,
  `status` tinyint(1) unsigned NOT NULL,
  `update_time` bigint(4) unsigned NOT NULL,
  `create_time` bigint(4) unsigned NOT NULL,
  PRIMARY KEY (`id`) USING BTREE,
  KEY `browse` (`post_id`,`user_id`) USING BTREE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4  row_format=compact;

提示：若是在新MySQL實例單獨刪除表browse_record，刪除失敗的話，那就直接drop掉新MySQL實例上的db_bbs庫，從新導入db_bbs全部表的建表語句，而後再執行下面的命令：

mysql -e "show tables from db_bbs" | grep -v  Tables_in_db_bbs| while read a; do mysql -e  "ALTER TABLE db_bbs.$a DISCARD TABLESPACE" ;done

從新導入表空間到新實例MySQL中:

[root@10-10-127-11 db_bbs]# mysql -e "show tables from db_bbs" | grep -v  Tables_in_db_bbs| while read a; do mysql -e  "ALTER TABLE db_bbs.$a import TABLESPACE" ;done
[root@10-10-127-11 db_bbs]#

到此處數據修復完成

校驗MySQL db_bbs庫中的表：

[root@10-10-127-11 db_bbs]# mysqlcheck -c db_bbs
db_bbs.browse_record                               OK
db_bbs.t_admin                                     OK
db_bbs.t_anonymous_code                            OK
db_bbs.t_apply                                     OK
db_bbs.t_attach                                    OK
db_bbs.t_banner                                    OK
db_bbs.t_banner_log                                OK
db_bbs.t_black_ip                                  OK
db_bbs.t_black_user                                OK
db_bbs.t_block_userbaseinfo                        OK
db_bbs.t_collect                                   OK
db_bbs.t_country_code                              OK
db_bbs.t_ct_goods                                  OK
db_bbs.t_ct_goods_record                           OK
db_bbs.t_ct_integral                               OK
db_bbs.t_ct_integral_record                        OK
db_bbs.t_ct_news                                   OK
db_bbs.t_ct_order                                  OK
db_bbs.t_feedback                                  OK
db_bbs.t_lexicon                                   OK
db_bbs.t_logs                                      OK
db_bbs.t_manage                                    OK
db_bbs.t_module                                    OK
db_bbs.t_post                                      OK
db_bbs.t_post_extend                               OK
db_bbs.t_post_video                                OK
db_bbs.t_realtime_message                          OK
db_bbs.t_recommend                                 OK
db_bbs.t_reply                                     OK
db_bbs.t_reward                                    OK
db_bbs.t_sensitive_word                            OK
db_bbs.t_system_message                            OK
db_bbs.t_user_health                               OK
db_bbs.t_user_message                              OK
db_bbs.t_user_read_module_log                      OK
db_bbs.t_userbaseinfo                              OK
db_bbs.t_userextendinfo                            OK
db_bbs.t_viewpoint                                 OK
db_bbs.t_white_ip                                  OK

2.四、獲取導入到新MySQL實例db_bbs庫中表記錄和和原來的庫test.txt表記錄文件對比

[root@10-10-127-11 ~]# for n in `mysql -e "use  db_bbs;show tables;"|sed '1d'`;do echo $n; mysql -e "use  db_bbs;select count(*) from $n;";done >test.txt11
和原來的庫test.txt表記錄文件對比。
[root@test02 ~]# vimdiff test.txt11 test.txt

表記錄徹底一致

到此處MySQL的數據修復完畢

參考資料：
https://mp.weixin.qq.com/s/r3KTPsFay292JnO0lgTLUg
https://www.cnblogs.com/jiangxu67/p/4744283.html
https://blog.csdn.net/Sonny_alice/article/details/80198200
https://www.cnblogs.com/jiangxu67/p/4744283.html