Identity

This is an attribute that is being used to mark the property of the class as an identity property.

Let us say you have a the table named [dbo].[Person] where the field Id is an identity.

CREATE TABLE [dbo].[Person]
(
    [Id] [bigint] IDENTITY(1,1) NOT NULL,
    [Name] [nvarchar](128) NOT NULL
)
ON [PRIMARY];
GO

And a model class named Person like below.

public class Person
{
    [Identity] // Identity decoration
    public long Id { get; set; }
    public string Name { get; set; }
}

By explicitly setting this attribute to any class property, you had overriden the auto-identification logic of the library. If you place this attribute in a property that is not really an identity from the database, then the library will use that property instead. By doing so, it may fail some of the operations.

To retrieve the identity property, you can use the IdentityCache object.

var identity = IdentityCache.Get<Person>();

Or via .NET CLR type.

var identity = IdentityCache.Get(typeof(Person));