How can I restore the MySQL root user’s full privileges?

If the GRANT ALL doesn't work, try:

1. Stop mysqld and restart it with the --skip-grant-tables option.
2. Connect to the mysqld server with just: mysql (i.e. no -p option, and username may not be required).

3. Issue the following commands in the mysql client:

   UPDATE mysql.user SET Grant_priv='Y', Super_priv='Y' WHERE User='root';

   FLUSH PRIVILEGES;

After that, you should be able to run GRANT ALL ON *.* TO 'root'@'localhost'; and have it work.

If you've deleted your root user by mistake you can do one thing:

1. Stop MySQL service
2. Run mysqld_safe --skip-grant-tables &
3. Type mysql -u root -p and press enter.
4. Enter your password
5. At the mysql command line enter: use mysql;

Then execute this query:

insert into `user` (`Host`, `User`, `Password`, `Select_priv`, `Insert_priv`, `Update_priv`, `Delete_priv`, `Create_priv`, `Drop_priv`, `Reload_priv`, `Shutdown_priv`, `Process_priv`, `File_priv`, `Grant_priv`, `References_priv`, `Index_priv`, `Alter_priv`, `Show_db_priv`, `Super_priv`, `Create_tmp_table_priv`, `Lock_tables_priv`, `Execute_priv`, `Repl_slave_priv`, `Repl_client_priv`, `Create_view_priv`, `Show_view_priv`, `Create_routine_priv`, `Alter_routine_priv`, `Create_user_priv`, `ssl_type`, `ssl_cipher`, `x509_issuer`, `x509_subject`, `max_questions`, `max_updates`, `max_connections`, `max_user_connections`) values('localhost','root','','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','','','','','0','0','0','0');

then restart the mysqld

EDIT: October 6, 2018

In case anyone else needs this answer, I tried it today using innodb_version 5.6.36-82.0 and 10.1.24-MariaDB and it works if you REMOVE THE BACKTICKS (no single quotes either, just remove them):

insert into user (Host, User, Password, Select_priv, Insert_priv, Update_priv, Delete_priv, Create_priv, Drop_priv, Reload_priv, Shutdown_priv, Process_priv, File_priv, Grant_priv, References_priv, Index_priv, Alter_priv, Show_db_priv, Super_priv, Create_tmp_table_priv, Lock_tables_priv, Execute_priv, Repl_slave_priv, Repl_client_priv, Create_view_priv, Show_view_priv, Create_routine_priv, Alter_routine_priv, Create_user_priv, ssl_type, ssl_cipher, x509_issuer, x509_subject, max_questions, max_updates, max_connections, max_user_connections) values('localhost','root','','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','','','','','0','0','0','0');

i also remove privileges of root and database not showing in mysql console when i was a root user, so changed user by mysql>mysql -u 'userName' -p; and password;

UPDATE mysql.user SET Grant_priv='Y', Super_priv='Y' WHERE User='root';FLUSH PRIVILEGES;

after this command it all show database's in root .

Thanks