Add project files.

CodeFirstExistingDatabase/PlutoContext.cs

@@ -0,0 +1,32 @@
+namespace CodeFirstExistingDatabase
+{
+    using System;
+    using System.Data.Entity;
+    using System.ComponentModel.DataAnnotations.Schema;
+    using System.Linq;
+
+    public partial class PlutoContext : DbContext
+    {
+        public PlutoContext()
+            : base("name=PlutoContext")
+        {
+        }
+
+        public virtual DbSet<Author> Authors { get; set; }
+        public virtual DbSet<Course> Courses { get; set; }
+        public virtual DbSet<Tag> Tags { get; set; }
+
+        protected override void OnModelCreating(DbModelBuilder modelBuilder)
+        {
+            modelBuilder.Entity<Author>()
+                .HasMany(e => e.Courses)
+                .WithOptional(e => e.Author)
+                .HasForeignKey(e => e.Author_Id);
+
+            modelBuilder.Entity<Course>()
+                .HasMany(e => e.Tags)
+                .WithMany(e => e.Courses)
+                .Map(m => m.ToTable("TagCourses").MapLeftKey("Course_Id"));
+        }
+    }
+}