problem migration and updating data using asp.net mvc5

hi guys

i create website using asp.net mvc5 but i have a problem of update-database,
 when i add-migration -name and i update-database
and when i running the application I get the same problem
"The model backing the 'StoreDbContext' context has changed since the database was created. Consider using Code First Migrations to update the database (microsoft.com/fwlink/?LinkId=238269)."

please help