.netcore EFcore basis for understanding

1. Create .netCore Web project. At this time, also lacks relationship with EF.

2. Then add classes Bolg. Post reference herein and https://docs.microsoft.com/en-us/ef/core/modeling/relational/fk-constraints

public class Blog
{
    public int BlogId { get; set; }
    public string Url { get; set; }

    public List<Post> Posts { get; set; }
}

public class Post
{
    public int PostId { get; set; }
    public string Title { get; set; }
    public string Content { get; set; }

    public int BlogId { get; set; }
    public Blog Blog { get; set; }
}

3. The new controller Blogs. Use "" The operation of the EF controller. "

This time the relevant libraries will be installed from the EF Nuget.

This class also generates context

public class MyEFTestContext : DbContext
    {
        public MyEFTestContext (DbContextOptions<MyEFTestContext> options)
            : base(options)
        {
        }

        public DbSet<MyEFTest.Models.Blog> Blog { get; set; }
    }

4. Run add-migration. Folder generated migration. The following will migrate files and snap.cs file.

can be seen. The migration file.

 modelBuilder.Entity("MyEFTest.Models.Post", b =>
                {
                    b.HasOne("MyEFTest.Models.Blog", "Blog")
                        .WithMany("Posts")
                        .HasForeignKey("BlogId")
                        .OnDelete(DeleteBehavior.Cascade);
                });

This specifies the foreign key relationships