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asp.net mvc - How to turn on identity-insert in .net core

I made a few tables in EF and entered in some seed data where I give value to a few columns with a primary key. When I run the application I am getting the error message:

Cannot insert explicit value for identity column in table 'Persons' when IDENTITY_INSERT is set to OFF.

How do I turn it on? I read on here to use:

[DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]

above the property that is a primary key. I am still getting the same error message unfortunately. Please help.

I added [DatabaseGenerated(DatabaseGeneratedOption.None)] to all my properties that have a primary key. When I ran the migration I can see that the identity column is removed, But I am still getting the same error message.

When I go into SQL SEO I can still see the identity column on my primary key. I tried refreshing the database. What am I doing wrong? The only thing I can do is go into properties and remove the identity, but why can't I do it the way mentioned above?

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In EF Core 1.1.2, I got this to work with transactions. In my "database initializer" that put seed data into the tables. I used the technique from this EF6 answer. Here's a sample of the code:

using (var db = new AppDbContext())
using (var transaction = db.Database.BeginTransaction())
{
    var user = new User {Id = 123, Name = "Joe"};
    db.Users.Add(user);
    db.Database.ExecuteSqlCommand("SET IDENTITY_INSERT MyDB.Users ON;");
    db.SaveChanges();
    db.Database.ExecuteSqlCommand("SET IDENTITY_INSERT MyDB.Users OFF");
    transaction.Commit();
}

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