Entity.

[Table("OrderLines", Schema = "Sales")]

    public class OrderLine
    {
        [Key]
        public long OrderLineID { get; set; }
    }

Try to get entity by ID

public virtual async Task GetByIdAsync(object id)
{
    if (id == null) throw new ArgumentNullException("Identifier is null");
    return await _entities.FindAsync(id);
}

Get an error System.AggregateException: "One or more errors occurred. (The key value at position 0 of the call to 'DbSet.Find' was of type 'int', which does not match the property type of 'long'.)"