EF 5 AddOrUpdate Duplicates data

Question

This is the code in the Seed method:

var city = new City { Name = \"A\" };

var nh = new List
{
    new Neigh { City = city, Name = \"N1\" },
           


        

Answer 1

You must start the script by checking whether the city already exists:

var city = context.Cities.FirstOrDefault(c => c.Name == "A") 
                                     ?? new City { Name = "A" };