There are 2 ways to import .sql database file in mySQL.
Select the database in which you wish to import MySQL file.
Import -> Browse for the .sql file and click on GO.
If you are lucky your database will be imported if not look for next 2 methods
If you have access to your webhost either direct or via SSH
The sql query to import .sql database is
mysql -h host -u databaseusername-p databasename< database.sql
host with your actual host (in most cases it would be localhost)
databaseusername with the user name assigned to access above database
databasename with your actual database name
database.sql with your actual .sql file