What can I do if Mysql cannot restore data because of direct backup of files? -Php Tutorial

Background my website was running all the time. suddenly, one day I found that my website was suspended. After troubleshooting, my database crashed. Login to Mysql: {code ...} to restart Mysql, the following error occurs: {code ...} because I found that Mysql has crashed, so I cannot back up data normally, so I thought of directly copying var... background

My website was running all the time. suddenly one day I found that my website had crashed. After troubleshooting, my database had crashed.
Login to Mysql:

ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (111)

To restart Mysql, the following error occurs:

stop:unknown instancestart:job failed to start

I found that Mysql has crashed, so I cannot back up data normally. I thought of directly copying files under/var/lib/mysql for data backup.

Question

After I reinstall Mysql, I replaced the previous backups under/var/lib/mysql/dbname. after frm, start Mysql and find that the backup data is not in use, or the data in the newly created database.
After searching, I learned that innodb has to replace ibdata1, so after I replace it, I cannot start my Mysql. the prompt is:

start:failed to start

How can I restore my previous data?

Reply content: Background

My website was running all the time. suddenly one day I found that my website had crashed. After troubleshooting, my database had crashed.
Login to Mysql:

ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (111)

To restart Mysql, the following error occurs:

stop:unknown instancestart:job failed to start

I found that Mysql has crashed, so I cannot back up data normally. I thought of directly copying files under/var/lib/mysql for data backup.

Question

After I reinstall Mysql, I replaced the previous backups under/var/lib/mysql/dbname. after frm, start Mysql and find that the backup data is not in use, or the data in the newly created database.
After searching, I learned that innodb has to replace ibdata1, so after I replace it, I cannot start my Mysql. the prompt is:

start:failed to start

How can I restore my previous data?

View the specific mysq error log file and solve the problem based on the error information.