private static void DeleteComment(EntityExerciseBlog db)
{
Comments commentInfo = db.Comments
.Single(c => c.Id == 2);
db.Comments.Remove(commentInfo);
db.SaveChanges();
}
private static void UpdateData(EntityExerciseBlog db)
{
Users userInfo = db.Users.Single(user => user.FullName == "Teng Qingshan");
string oldName = userInfo.FullName;
userInfo.FullName = "Malkata Tenga";
db.SaveChanges();
}
private static void SelectAuthorOfSpecificPost(EntityExerciseBlog db)
{
var author = db.Users
.SelectMany(user => user.Posts, (user, post) => new { user.UserName, user.FullName, post.Id })
.Single(post => post.Id == 4);
Console.WriteLine("Username: {0}", author.UserName);
Console.WriteLine("Posts Title: {0}", author.FullName);
Console.WriteLine();
}
private static void DeletePost(EntityExerciseBlog db)
{
Posts postInfo = db.Posts
.Single(p => p.Id == 22);
db.Comments.RemoveRange(postInfo.Comments);
postInfo.Tags.Clear();
db.Posts.Remove(postInfo);
db.SaveChanges();
}
private static void JoinAuthorWithTitles(EntityExerciseBlog db)
{
var users = db.Users
.SelectMany(user => user.Posts, (user, post) => new { user.UserName, post.Title });
foreach (var user in users)
{
Console.WriteLine("Username: {0}", user.UserName);
Console.WriteLine("Posts Title: {0}", user.Title);
Console.WriteLine();
}
}
private static void CreateNewPost(EntityExerciseBlog db)
{
var post = new Posts
{
AuthorId = 2,
Title = "Ne post from author 2",
Body = "Something written from author 2",
Date = DateTime.Now
};
db.Posts.Add(post);
db.SaveChanges();
}
private static void ListAllPosts(EntityExerciseBlog db)
{
List <Posts> posts = db.Posts.Select(post => post).ToList();
foreach (Posts post in posts)
{
Console.WriteLine("Title: {0}", post.Title);
Console.WriteLine("AuthorID: {0}", post.Id);
Console.WriteLine("Comments count: {0}", post.Comments.Count());
Console.WriteLine("Tags count: {0}", post.Tags.Count());
Console.WriteLine();
}
}
private static void SelectAuthors(EntityExerciseBlog db)
{
List <Users> users = db.Users.Select(user => user)
.Where(user => user.Posts.Count > 0)
.ToList();
foreach (var user in users)
{
Console.WriteLine("Username: {0}", user.UserName);
Console.WriteLine("Full name: {0}", user.FullName);
Console.WriteLine("Posts count: {0}", user.Posts.Count());
Console.WriteLine();
}
}
private static void ListPostsWithTitleAndBody(EntityExerciseBlog db)
{
var posts = db.Posts.Select(p => new
{
p.Title,
p.Body
}).ToList();
foreach (var post in posts)
{
Console.WriteLine("Title: {0}", post.Title);
Console.WriteLine("Content: {0}", post.Body);
Console.WriteLine();
}
}
private static void OrderUsersByUsername(EntityExerciseBlog db)
{
var users = db.Users.Select(p => new
{
p.UserName,
p.FullName
})
.OrderBy(user => user.UserName).ToList();
foreach (var user in users)
{
Console.WriteLine("Username: {0}", user.UserName);
Console.WriteLine("Full name: {0}", user.FullName);
Console.WriteLine();
}
}
static void Main(string[] args)
{
EntityExerciseBlog db = new EntityExerciseBlog();
var posts = db.Posts
.Select(post => new
{
Tags = post.Tags.Select(t => t.Name == "security"),
}
)
.ToList();
//string targetTag = "it";
//var tagIt = db.Tags.Single(t => t.Name == "it");
//var posts = db.Posts
// .SelectMany(post => post.Tags, (post, tag) => new PostWithTagName{ PostID = post.Id, Body = post.Body, TagName = tag.Name }).ToList();
//foreach (var post in posts)
//{
// if (post.TagName != "it")
// {
// Console.WriteLine("postId: {0}", post.PostID);
// Console.WriteLine("Posts body: {0}", post.Body);
// Console.WriteLine();
// }
//}
//ListAllPosts(db);
//ListAllUsers(users);
//ListPostsWithTitleAndBody(db);
//OrderUsersByUsername(db);
//OrderUsersByUsernameAndFullname(db);
//SelectAuthors(db);
//JoinAuthorWithTitles(db);
//SelectAuthorOfSpecificPost(db);
//OrderAuthorsOfPosts(db);
//CreateNewPost(db);
//UpdateData(db);
//DeleteComment(db);
//DeletePost(db);
}
private static void ListAllUsers(EntityExerciseBlog db)
{
var users = db.Users.Select(user => new
{
ID = user.Id,
Name = user.FullName,
CommentsCount = user.Comments.Count(),
PostsCount = user.Posts.Count()
})
.ToList();
foreach (var user in users)
{
Console.WriteLine("Id: {0}", user.ID);
Console.WriteLine("Name: {0}", user.Name);
Console.WriteLine("Comments count: {0}", user.CommentsCount);
Console.WriteLine("Posts count: {0}", user.PostsCount);
Console.WriteLine();
}
}
private static void OrderAuthorsOfPosts(EntityExerciseBlog db)
{
var users = db.Users.Select(user => new
{
Username = user.UserName,
Fullname = user.FullName,
postsCount = user.Posts.Count(),
id = user.Id
})
.Where(user => user.postsCount > 0)
.OrderByDescending(user => user.id)
.ToList();
foreach (var user in users)
{
Console.WriteLine("Username: {0}", user.Fullname);
Console.WriteLine("Full name: {0}", user.Username);
Console.WriteLine();
}
}
