The Entity Framework can automatically create/update/drop databases when the application runs. We can specify that, this should be done every time application runs or only when the model is out of sync with the existing database or in other word it runs whenever model changes. You spent time to insert records in database and when you made any changes in model, Entity Framework deletes your database as well as records.
In this quick code you will learn how to initialize var so that it works like null or empty. Technically, this is not possible.