Step #1: Make Backups, Always!
Whenever modifying files on a server it’s always best practice to take some form of a backup beforehand. This ensures you have a way to revert changes if something goes awry; it’s also beneficial because it helps track when and what changes were made.
While logged into SSH with the root user, do the following:
cp -a /usr/my.cnf{,.strict.bak}
cp -a /etc/my.cnf{,.strict.bak}
Step #2: Disable MySQL Strict Mode
Depending on the server and the current configurations you may need to edit one, or both, of the following files on the server. Generally, the relevant configuration lines are only in one of them, however, it could be in either one without causing issues; so generally it’s best to check both.
To edit the files, you will open the file with your favorite command line editor. In this example, we use ‘vim’.
vim /usr/my.cnf
vim /etc/my.cnf
Within each file above you will be looking for a line with the following content:
sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES
If you find a line similar to the above that is setting the `sql_mode` variable then you will need to replace it with the following line to disable MySQL strict mode.
sql_mode=""
Once this adjustment has been made, or you’ve confirmed the file does not need to be adjusted you will then save and close the file.
Step #3: Restart the MySQL Service
Finally, to make these changes effective you will need to restart the MySQL service as it will only read the configuration files when it initially loads up. In order to force MySQL to use the new configuration files you will do the following:
For CentOS 7 servers:systemctl restart mysql
For CentOS 6 and prior:/etc/init.d/mysql restart
After issuing this command on the server the MySQL service will be restarted and will load the changes made. If all the directions were followed and completed, then MySQL strict mode should now be disabled.
To verify that the process was completed properly you can run the following:
mysql -e "SELECT @@sql_mode;"
The output may look similar to the following:
+--------------------------------------------+
| @@sql_mode
+--------------------------------------------+
| NO_AUTO_CREATE_USER
+--------------------------------------------+
