Question

I am using EF5 and Code First to create database. When Entity has Id field, EF create such field as Primary Key in database and set Identity specification to true(auto generated value). How to set Identity specification to false by default?

Answer 1

If you don’t want to use identity keys you have several options.

Option 1: You can globally turn off this feature by removing StoreGeneratedIdentityKeyConvention:

public class YourContext : DbContext {
    protected override void OnModelCreating(DbModelBuilder modelBuilder) {
        modelBuilder.Conventions.Remove<StoreGeneratedIdentityKeyConvention>();
    }
}

You can selectively select keys and change the behavior for them by either applying attribute or fluent mapping.

Option 2: Attribute:

public class MyEntity {
    [DatabaseGenerated(DatabaseGeneratedOption.None)]
    public int Id { get; set; }        
}

Option 3: Fluent API:

public class YourContext : DbContext {
    protected override void OnModelCreating(DbModelBuilder modelBuilder) {
        modelBuilder.Entity<MyEntity>()
                    .Property(e => e.Id)
                    .HasDatabaseGeneratedOption(DatabaseGeneratedOption.None);
    }
}