using System;

using System.Collections;

using System.Collections.Generic;

using System.Linq;

using System.Data.Linq;

public class Program

{

    public static void Main()

    {

                    List<Post> posts = new List<Post>()

            {

                new Post { PostId = 1,Body="hi",PostDate=DateTime.Now,Title="post 1",Draft="" },

                new Post { PostId = 2,Body="hiii",PostDate=DateTime.Now,Title="post 2",Draft="" },

                new Post { PostId = 3,Body="hiiiii",PostDate=DateTime.Now,Title="post 3",Draft="" },

                new Post { PostId = 4,Body="hi hh",PostDate=DateTime.Now,Title="post 4",Draft="" },

            };

​

            List<Category> categories = new List<Category>()

            {

                new Category {CategoryId=1,CategoryName="Cat 1"  },

                new Category {CategoryId=2,CategoryName="Cat 2"  },

                new Category {CategoryId=3,CategoryName="Cat 3"  },

                new Category {CategoryId=4,CategoryName="Cat 4"  }

            };

​

            List<PostCategory> postcategories = new List<PostCategory>()

            {

                new PostCategory { CategoryId = 1, PostId = 4},

                new PostCategory { CategoryId = 2, PostId = 3},

                new PostCategory { CategoryId = 3, PostId = 1},

                new PostCategory { CategoryId = 4, PostId = 2},

            };

​

            List<Author> authors = new List<Author>()

            {

                new Author { AuthorId = 1, AuthorName = "Author 1"},

                new Author { AuthorId = 2, AuthorName = "Author 2"},

                new Author { AuthorId = 3, AuthorName = "Author 3"},

                new Author { AuthorId = 4, AuthorName = "Author 4"},

            };

​

            List<PostTag> tagposts = new List<PostTag>()

            {

                new PostTag { PostId = 1, TagId = 4},

                new PostTag { PostId = 1, TagId = 2},

                new PostTag { PostId = 2, TagId = 2},

                new PostTag { PostId = 3, TagId = 1},

                new PostTag { PostId = 4, TagId = 3}

            };

​

            List<Tag> tags = new List<Tag>()

            {

                new Tag { TagId = 1, TagName ="Tag 1"},

                new Tag { TagId = 2, TagName ="Tag 2"},

                new Tag { TagId = 3, TagName ="Tag 3"},

                new Tag { TagId = 4, TagName ="Tag 4"},

            };

​

            var results = from p in posts

                          join pc in postcategories on p.PostId equals pc.PostId

                          join c in categories on pc.PostId equals c.CategoryId

                          join a in authors on pc.PostId equals a.AuthorId

                          join tp in tagposts on p.PostId equals tp.PostId

                          join t in tags on tp.TagId equals t.TagId

                          group new { t, p, c, a } by tp.PostId into g

​

                          select new BlogViewModel

                          {

                              Post = g.First().p,

                              Category = g.First().c,

                              Author = g.First().a,

                              Tags = g.Select(x=>x.t)

                          };

​

        foreach(var item in results)

        {

            Console.WriteLine(string.Join(Environment.NewLine,"Post: "+ item.Post.Title,"Category: "+item.Category.CategoryName,"Author: "+ item.Author.AuthorName,"Tags: "+string.Join(",",tags.Select(x=>x.TagName))));

​

            Console.WriteLine();

        }

    }

}

​

​

    public class Post

    {

     public int PostId {get;set;}

     public string Title {get;set;}

     public DateTime PostDate {get;set;}

     public string Body {get;set;}

     public string Draft {get;set;}

    }

​

    public class Category

    {

    public int CategoryId {get;set;}

    public string CategoryName {get;set;}

    }

​

    public class PostCategory

    {

    public int PostId {get;set;}

    public int CategoryId {get;set;}

    }

​

    public class Author

    {

    public int AuthorId {get;set;}

    public string AuthorName {get;set;}

    }

​

    public class PostAuthor

    {

    public int AuthorId {get;set;}

    public int PostId {get;set;}

    }

​

    public class Tag

    {

    public int TagId {get;set;}

    public string TagName {get;set;}

    }

​

    public class PostTag

    {

    public int PostId {get;set;}

    public int TagId {get;set;}

    }

​

    public class BlogViewModel

    {

        public Post Post { get; set; }

        public Category Category { get; set; }

        public Author Author { get; set; }

        public IEnumerable<Tag> Tags { get; set; }

    }