问题
With Ubuntu, I previously created a mysql database using the following code in the terminal:
$ my sql -u root -p
Then within mysql:
CREATE DATABASE securities_master;
I was trying to use file explorer to view the contents related to this database. But because I did not have permissions to open the folder /var/lib/mysql I wanted to change the permissions on this folder. I did some searching on stackoverflow, and without fully understanding what I was doing, I used something like the following (my username being wei):
sudo chown -R root:wei /var/lib/mysql
OR (unfortunately I had since closed terminal window so not sure exactly what I typed)
sudo chown -R wei:wei /var/lib/mysql
OR
sudo chown -R wei /var/lib/mysql
This allowed me to view inside the directory and see my files, so I thought I was making progress. However, once I had done this I realized that when I tried to USE the database in mysql:
USE securities_database;
I was getting an error message like:
ERROR 1049 (42000): Unknown database 'securities_master'
I believe this is related to my use of chown earlier. Upon looking into this with further stackoverflow searches, I'm now under the impression I shouldn't be willy nilly taking away root ownership of some files from root as "bad things can happen". I've tried to restore root ownership with:
sudo chown -R root /var/lib/mysql
AND/OR:
sudo chown -R root:root /var/lib/mysql
But unfortunately I seem to still get the same error message.
I apologize if my question seems so basic, or such a rookie error, total newbie to Ubuntu, Linux and mysql here. Thanks.
回答1:
The normal ownership of everything in /var/lib/mysql is mysql:mysql. So you should be able to fix it with:
sudo chown -R mysql:mysql /var/lib/mysql
来源：https://stackoverflow.com/questions/43593736/used-chown-for-var-lib-mysql-to-change-owner-from-root-now-getting-error-1049