modelSelfRefferenceCS
namespace Lab_2
{
    using System;
    using System.Data.Entity;
    using System.Linq;
    using System.Collections.Generic;
    using System.ComponentModel.DataAnnotations;
    using System.ComponentModel.DataAnnotations.Schema;
    public class ModelSelfReferences : DbContext
    {
        public ModelSelfReferences()
        : base("name=ModelSelfReferences")
        {
        }
        // public virtual DbSet<MyEntity> MyEntities { get; set; }
        public virtual DbSet<SelfReference> SelfReferences { get; set; }
        protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {
            base.OnModelCreating(modelBuilder);
            modelBuilder.Entity<SelfReference>()
            .HasMany(m => m.References)
            .WithOptional(m => m.ParentSelfReference);
        }
    }

    public class ProductContext : DbContext
    {
        public DbSet<Product> Products { get; set; }
        public ProductContext() : base("name=ProductContext")
        { }
        protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {
            base.OnModelCreating(modelBuilder);
            modelBuilder.Entity<Product>()
            .Map(m =>
            {
                m.Properties(p => new { p.SKU, p.Description, p.Price });
                m.ToTable("Product", "BazaDeDate");
            })
            .Map(m =>
            {
                m.Properties(p => new { p.SKU, p.ImageURL });
                m.ToTable("ProductWebInfo", "BazaDeDate");
            });
        }
    }

    public class PhotographContext : DbContext
    {
        public DbSet<Photograph> Photographs { get; set; }
        public PhotographContext() : base("name=PhotographContext")
        { }
        protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {
            base.OnModelCreating(modelBuilder);
            modelBuilder.Entity<Photograph>()
            .HasRequired(p => p.PhotographFullImage)
            .WithRequiredPrincipal(p => p.Photograph);
            modelBuilder.Entity<Photograph>().ToTable("Photograph",
            "BazaDeDate");
            modelBuilder.Entity<PhotographFullImage>().
            ToTable("Photograph", "BazaDeDate");
        }

    }

    public class BusinessContext : DbContext
    {
        public DbSet<Business> Businesses { get; set; }
        public BusinessContext() : base("name=BusinessContext")
        { }
    }

    public class EmployeeContext : DbContext
    {
        public DbSet<Employee> Employees { get; set; }
        public EmployeeContext() : base("name=EmployeeContext")
        { }
        protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {
            base.OnModelCreating(modelBuilder);
            modelBuilder.Entity<Employee>()
            .Map<FullTimeEmployee>(m =>
            m.Requires("EmployeeType").HasValue(1))
            .Map<HourlyEmployee>(m =>
            m.Requires("EmployeeType").HasValue(2));
        }

    }

    public class PhotographFullImage
    {
        [Key]
        public int PhotoId { get; set; }
        public byte[] HighResolutionBits { get; set; }
        [ForeignKey("PhotoId")]
        public virtual Photograph Photograph { get; set; }
    }


    //public class MyEntity
    //{
    //    public int Id { get; set; }
    //    public string Name { get; set; }
    //}
    public class SelfReference
    {
        [Key]
        [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
        public int SelfReferenceId { get; private set; }
        public string Name { get; set; }
        public int? ParentSelfReferenceId { get; private set; }
        [ForeignKey("ParentSelfReferenceId")]
        public SelfReference ParentSelfReference { get; set; }
        public virtual ICollection<SelfReference> References { get; set; }
        public SelfReference()
        {
            References = new HashSet<SelfReference>();
        }
    }

    public class Product
    {
        [Key]
        [DatabaseGenerated(DatabaseGeneratedOption.None)]
        public int SKU { get; set; }
        public string Description { get; set; }
        public decimal Price { get; set; }
        public string ImageURL { get; set; }
    }

    public class Photograph
    {
        [Key]
        [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
        public int PhotoId { get; set; }
        public string Title { get; set; }
        public byte[] ThumbnailBits { get; set; }
        [ForeignKey("PhotoId")]
        public virtual PhotographFullImage PhotographFullImage { get; set; }
    }

    //scenario 4
    [Table("Business", Schema = "BazaDeDate")]
    public class Business
    {
        [Key]
        [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
        public int BusinessId { get; protected set; }
        public string Name { get; set; }
        public string LicenseNumber { get; set; }
    }

    [Table("eCommerce", Schema = "BazaDeDate")]
    public class eCommerce : Business
    {
        public string URL { get; set; }
    }
    [Table("Retail", Schema = "BazaDeDate")]
    public class Retail : Business
    {
        public string Address { get; set; }
        public string City { get; set; }
        public string State { get; set; }
        public string ZIPCode { get; set; }
    }


    //scenario5
    public abstract class Employee
    {
        [Key]
        [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
        public int EmployeeId { get; protected set; }
        public string FirstName { get; set; }
        public string LastName { get; set; }
    }

    public class FullTimeEmployee : Employee
    {
        public decimal? Salary { get; set; }
    }
    public class HourlyEmployee : Employee
    {
        public decimal? Wage { get; set; }
    }

}