Why Does MySQL Treat `localhost` Differently Than `127.0.0.1`?

MySQL localhost != 127.0.0.1?

This discrepancy arises due to MySQL's socket usage when invoked without a hostname or with the 'localhost' hostname. As demonstrated below, using MySQL with the hostname '127.0.0.1' connects via TCP/IP sockets:

$ mysql -u root -h 127.0.0.1 -e 'show tables' created_from_host;
+-----------------------------+
| Tables_in_created_from_host |
+-----------------------------+
| test                        |
+-----------------------------+

However, using 'localhost' connects via UNIX sockets, resulting in the following error:

$ mysql -u root -h localhost -e 'show tables' created_from_host;
ERROR 1049 (42000): Unknown database 'created_from_host'

How to grant ALL privileges on ALL databases from ALL hosts for root?

To grant unrestricted privileges to the 'root' user, execute the following SQL statement:

GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' WITH GRANT OPTION;

Additional Considerations:

• skip_networking variable: Ensure this variable is set to 'OFF' to enable TCP/IP connections.
• 'user' table: Check the 'mysql.user' table to verify that the 'root' user has host records for both 'localhost' and '127.0.0.1'.

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