C# EF Code First Seeding Data - Keeps Adding (Instead of updating) [duplicate]

Question

I have a list of type User and when I try to seed my db to reflect updates, it is simply adding all the entries again. I will share my code I am executing in my Seed() method. I wish to just update the records (but keep the add functionality), if they already exist. Any thoughts?

List<User> users = new List<User>();

users.Add(new User { FirstName = "Dee", LastName = "Reynolds" });
users.Add(new User { FirstName = "Rickety", LastName = "Cricket" });

users.ForEach(b => context.Users.AddOrUpdate(b));

Answer 1

You simply need to specify the key you want to check against when you are adding/updating the record. So for a new User you would do this:

context.Users.AddOrUpdate(x => x.UserName, //Or some other field that you know will be consistant
    new User { FirstName = "Dee", LastName = "Reynolds" }
);