Error establishing a database connection in godaddy.com

Did you change http://localhost to http://yoursite.com in your .sql file

Also ,check your client website database in phpmyadmin ,upload .sql file to it and also make sure your localhost databse have same prefix as your client ,generally it is wp_ but if different change it .

connect to your client website through FTP and upload all files or only wp-content folder

It would fix the problem

Regards