Sometimes, you want to backup individual databases in MySQL to move to a different server. This part is easy using mysqldump:

shell> mysqldump -u root -p --databases db1 db2 ... > backup.sql

The problem is, what happens when you want to backup the permissions associated with these databases? Well, here are a few queries to help you out.

-- Grab the users with global permissions, 
-- with permissions to the databases you want, 
-- and tables/stored procedures in it.
mysql> SELECT u.* INTO OUTFILE '/tmp/user.txt'
	FIELDS TERMINATED BY ',' OPTIONALLY ENCLOSED BY '"' ESCAPED BY '\\'
	LINES TERMINATED BY '\n'
	FROM
		mysql.user u
	WHERE
		u.Select_priv='Y'
	UNION
	SELECT u.*
	FROM
		mysql.user u,
		mysql.db d
	WHERE
		d.Db IN('db1', 'db2', ...) AND
		d.User = u.user
	UNION
	SELECT u.*
	FROM
		mysql.user u,
		mysql.tables_priv

I had an issue come up recently that involved some confusion over permissions for the same user, connecting through different interfaces. For example, say you have a server with the public IP address of 192.168.0.1. You could connect to it from the local machine using the following commands:

shell> mysql -h localhost           # Connects through the socket file
shell> mysql -h 127.0.0.1           # Connects through the loopback interface
shell> mysql -h 192.168.0.1         # Connects through the network interface

They all connect to the local server, but they can all have different permissions. Here are a couple of rules to make your life easier:

• Don’t use @127.0.0.1, unless you absolutely can’t use the socket file for some reason. Connecting through @localhost is usually faster than the loopback device, and it’s