This can happen as the HTTP post size is limited to a smaller number. The best way to restore your SQL database is by logging into SSH. Be sure that you've already created your MySQL Database from inside of the control panel.

1. Upload your SQL file to your root directory /home/username*/
2. Load up PuTTy or your favourite terminal client.
3. Run the following command
   

   mysql -u your_mysql_user -p your_mysql_db < /home/username*/sqlfile.sql

4. Enter in your database password and press enter.

Once completed it will return to bash.