I have this two class :
public class BlogPost
{
public string Id { get; set; }
public string Title { get; set; }
public string Category { get; set; }
public string Content { get; set; }
public DateTime PublishedAt { get; set; }
public string[] Tags { get; set; }
public BlogComment[] Comments { get; set; }
}
public class BlogComment
{
public string Id { get; set; }
public string Title { get; set; }
public string Content { get; set; }
}
and add to documents like this :
// Creating a new instance of the BlogPost class
BlogPost post = new BlogPost()
{
Title = "Hello RavenDB",
Category = "RavenDB",
Content = "This is a blog about RavenDB",
Comments = new BlogComment[]
{
new BlogComment() {Title = "Unrealistic", Content = "This example is unrealistic"},
new BlogComment() {Title = "Nice", Content = "This example is nice"}
}
};
is there a way that my comments have Identity key like my BlogPost class?
and another question:
is there a way that get comment object without using post. something like this :
using( var session = doc.OpenSession() )
{
return session.Load<BlogComment>( ID );
}
or
using( var session = doc.OpenSession() )
{
return ( from comment in session.Query<BlogComment>()
where comment.Title == title
select comment ).FirstOrDefault();
}
You can just have an integer property on BlogPost, increment that and set that value whenever you add a new comment. That would give you identity style ids within the scope of the post.
Related
I have two documents Ticket and MenuItem i have created index with TransformResults but problem is i am getting null value for Loaded document in transform
public class Ticket
{
public int ID { get; set; }
public int ItemId { get; set; }
public string ItemName { get; set; }
public int Price { get; set; }
}
public class MenuItem
{
public int ID { get; set; }
public string ItemName { get; set; }
public string PriceCategory { get; set; }
}
i have created a index like
public class TicketItemGross : AbstractIndexCreationTask<Ticket, TicketItemGross.TicketItemDetails>
{
public class TicketItemDetails
{
public string ID { get; set; }
public string ItemId { get; set; }
public string ItemName { get; set; }
public int Price { get; set; }
public string PriceCategory { get; set; }
}
public TicketItemGross()
{
Map = docs => from doc in docs
select new
{
ID = doc.ID,
ItemId=doc.ItemId,
ItemName=doc.ItemName,
Price=doc.Price
};
TransformResults = (database, docs) => from m in docs
let d = database.Load<MenuItem>(m.ID)
select new
{
ID = m.ID,
ItemId = m.ItemId,
ItemName = m.ItemName,
Price = m.Price,
PriceCategory=d.PriceCategory
};
}
}
and the problem is that when i query data. I get null for PriceCategory but for all other fields i get correct value
here is query
IEnumerable<TicketItemGross.TicketItemDetails> list;
using (var session = store.OpenSession())
{
list = session.Query<TicketItemGross.TicketItemDetails, TicketItemGross>();
}
This is happening because you are using integer IDs. When you call database.Load in your transform, you'll need to manually convert it to a string ID.
database.Load<MenuItem>("MenuItems/" + m.ID)
This is one of several places where Raven gets confused if you use integer or guid IDs. If you use string ids, you won't have this problem.
Also, you might consider using a results transformer instead. They are easier than index transformers, which are now obsolete.
I am new to Asp.net MVC and working on a simple blog application (Asp.Net MVC5, EF6) for learning.
I am using repository pattern for the solution architecture with EF Code first migration, Ninject for DI. On the client side, I am using jQuery Grid for Admin to manage Posts, Categories and Tags.
- Blog.Model: Post.cs, Category.cs, Tags.cs
public class Post
{
[Required(ErrorMessage = "Id is required")]
public int Id { get; set; }
[Required(ErrorMessage = "Title is required")]
[StringLength(500, ErrorMessage = "Title cannot be more than 500 characters long")]
public string Title { get; set; }
[Required(ErrorMessage = "Short description is required")]
public string ShortDescription { get; set; }
[Required(ErrorMessage = "Description is required")]
public string Description { get; set; }
public bool Published { get; set; }
[Required(ErrorMessage = "PostedOn date is required")]
public DateTime PostedOn { get; set; }
public DateTime? ModifiedOn { get; set; }
[ForeignKey("Category")]
public virtual int CategoryId { get; set; }
public virtual Category Category { get; set; }
public virtual IList<Tag> Tags { get; set; }
}
public class Category
{
[Key]
public int CategoryId { get; set; }
[Required(ErrorMessage = "Category Name is required")]
[StringLength(500,ErrorMessage = "Category name length cannot exceed 500")]
public string Name { get; set; }
[Required(ErrorMessage = "Category Name is required")]
[StringLength(500, ErrorMessage = "Category name length cannot exceed 500")]
public string Description { get; set; }
[JsonIgnore]
public virtual IList<Post> Posts { get; set; }
}
public class Tag
{
public int Id { get; set; }
[Required(ErrorMessage = "Name is required")]
[StringLength(500, ErrorMessage = "Name length should not exceed 500 characters")]
public string Name { get; set; }
public string Description { get; set; }
[JsonIgnore]
public IList<Post> Posts { get; set; }
}
- Blog.Repository: BlogRepository, IBlogRepository, BlogContext
public interface IBlogRepository
{
int SavePost(Post post);
//Other methods...
}
public class BlogRepository : BlogContext, IBlogRepository
{
public BlogContext _db;
public BlogRepository(BlogContext db)
{
_db = db;
}
public int SavePost(Post post)
{
_db.Posts.Add(post);
_db.SaveChanges();
return post.Id;
}
//Other implementations...
}
public class BlogContext : DbContext, IDisposedTracker
{
public BlogContext() : base("BlogDbConnection") { }
public DbSet<Post> Posts { get; set; }
public DbSet<Tag> Tags { get; set; }
public DbSet<Category> Categories { get; set; }
public bool IsDisposed { get; set; }
protected override void Dispose(bool disposing)
{
IsDisposed = true;
base.Dispose(disposing);
}
- Blog.Web: AdminController.cs, NinjectWebCommon.cs
AdminController sends/consumes data in Json format.
public class AdminController : Controller
{
private readonly IBlogRepository _blogRepository;
public AdminController(IBlogRepository blogRepository)
{
_blogRepository = blogRepository;
}
//POST: /Admin/CreatePost
[HttpPost, ValidateInput(false)]
public ContentResult CreatePost([ModelBinder(typeof(PostModelBinder))] Post model)
{
string json;
ModelState.Clear();
if (TryValidateModel(model))
{
var id = _blogRepository.SavePost(model);
json = JsonConvert.SerializeObject(
new
{
id = id,
success = true,
message = "Post saved successfully."
});
}
else
{
json = JsonConvert.SerializeObject(
new
{
id = 0,
success = false,
message = "Post not saved."
});
}
return Content(json, "application/json");
}
}
public static class NinjectWebCommon
{
private static void RegisterServices(IKernel kernel)
{
kernel.Bind<BlogContext>().ToSelf(); //This isn't helping either
kernel.Bind<IBlogRepository>().To<BlogRepository>();
}
}
I am using Custom Model Binding because I was getting validation exception while saving post since list of Categories and Tags received from grid do not map to actual objects in the application model. Therefore in the custom model binding, I am populating Post object with actual objects received from grid. This Post object is Sent to controller which Save to database using DbContext and Repository.
public class PostModelBinder : DefaultModelBinder
{
public override object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
{
var post = (Post)base.BindModel(controllerContext, bindingContext);
**var blogRepository = new BlogRepository(new BlogContext());**//I think here I need to inject the dependency for BlogContext, but don't know how to do that.
if (post.Category != null)
{
post.Category = blogRepository._db.Categories.AsNoTracking().Single(c => c.CategoryId == post.Category.CategoryId);
}
var tags = bindingContext.ValueProvider.GetValue("Tags").AttemptedValue.Split(',');
if (tags.Length > 0)
{
post.Tags = new List<Tag>();
foreach (var tag in tags)
{
var id = int.Parse(tag.Trim());
post.Tags.Add(blogRepository._db.Tags.AsNoTracking().Single(t => t.Id == id));
}
}
if (bindingContext.ValueProvider.GetValue("oper").AttemptedValue.Equals("edit"))
post.ModifiedOn = DateTime.UtcNow;
else
post.PostedOn = DateTime.UtcNow;
return post;
}
}
Issue: When the Post is saved, data context inserts new rows for Category and Tags in their respective tables. The newly created post refers to new Category (Id:22) under Foreign key column.
Post:
Category:
Tag:
I think the reason for this is that when entity is saved it is attached to a different ObjectContext and I need to attach it to current context but do not know how? I found similar question asked before but there isn't an accepted answer to that. Any help would be greatly appreciated.
I was able to resolve above issue by attaching category and tags value to objectcontext manually, which indicates EF the changes it needs to make. This way it doesn't create new entries in Category and Tag's parent tables.
public int SavePost(Post post)
{
//attach tags to db context for Tags to tell EF
//that these tags already exist in database
foreach (var t in post.Tags)
{
_db.Tags.Attach(t);
}
//tell EF that Category already exists in Category table
_db.Entry(post.Category).State = EntityState.Modified;
_db.Posts.Add(post);
_db.SaveChanges();
return post.Id;
}
public void EditPost(Post post)
{
if (post == null) return;
//get current post from database
var dbPost = _db.Posts.Include(p => p.Tags).SingleOrDefault(p => p.Id == post.Id);
//get new list of tags
var newTags = post.Tags.Select(tag => new Tag() { Id = tag.Id, Name = tag.Name, Description = tag.Description }).ToList();
if (dbPost != null)
{
//get category from its parent table and assign to db post
dbPost.Category = _db.Categories.Find(post.Category.CategoryId); ;
//set scalar properties
_db.Entry(dbPost).CurrentValues.SetValues(post);
//remove tags from post in database
foreach (var t in dbPost.Tags.ToList())
{
if (!newTags.Contains(t))
{
dbPost.Tags.Remove(t);
}
}
//add tags to post in database
foreach (var t in newTags)
{
if (dbPost.Tags.All(p => p.Id != t.Id))
{
var tagInDb = _db.Tags.Find(t.Id);
if (tagInDb != null)
{
dbPost.Tags.Add(tagInDb);
}
}
}
}
//save changes
_db.SaveChanges();
}
I have and entity framework project exposed via a data service:
public class VersionContext : DbContext
{
public DbSet<VersionTreeEntry> VersionTreeEntries { get; set; }
public DbSet<PluginState> PluginStates { get; set; }
public static void SetForUpdates()
{
Database.SetInitializer(new MigrateDatabaseToLatestVersion<VersionContext, Configuration>());
}
}
public class VersionTreeEntry
{
public VersionTreeEntry()
{
Children = new List<VersionTreeEntry>();
PluginStates = new List<PluginState>();
}
[Key]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public long Id { get; set; }
public virtual ICollection<VersionTreeEntry> Children { get; set; }
public virtual ICollection<PluginState> PluginStates { get; set; }
public virtual VersionTreeEntry Ancestor { get; set; }
/// <summary>
/// Links to the ProtoBufDataItem Id for the session state.
/// </summary>
public int DataId { get; set; }
public string Notes { get; set; }
[Required]
public DateTime TimeStamp { get; set; }
[MinLength(1, ErrorMessage = "Tag cannot have a zero length")]
[MaxLength(20, ErrorMessage = "A tag name cannot contain over 20 characters")]
public string Tag { get; set; }
public bool IsUiNodeExpanded { get; set; }
[Required]
public string Version { get; set; }
[Required]
public string SessionName { get; set; }
}
public class PluginState
{
[Key]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public long Id { get; set; }
public string PluginName { get; set; }
[Required]
public byte[] Data { get; set; }
}
As far as I can see, the data classes are defined correctly. I try to create some new objects and add them into the context, with their relations intact:
var session = new Session();
session.SessionName = "My new session";
VersionTreeEntry versionTreeEntry = new VersionTreeEntry();
versionTreeEntry.SessionName = session.SessionName;
versionTreeEntry.Version = Assembly.GetExecutingAssembly().GetName().Version.ToString();
versionTreeEntry.TimeStamp = DateTime.Now;
_versionContext.AddToVersionTreeEntries(versionTreeEntry);
foreach (var plugin in session.Plugins)
{
using (var ms = new MemoryStream())
{
plugin.SaveState(ms);
PluginState state = new PluginState();
state.PluginName = plugin.PluginName;
state.Data = ms.ToArray();
versionTreeEntry.PluginStates.Add(state);
}
}
_versionContext.SaveChanges();
The problem is that the PluginState instances never actually get added to the database. If I add code to add them manually to the context, they do get added, but the foreign key pointing back to the VersionTreeEntry is null.
Again, this is a WCF DataService rather than vanilla EF, any idea what might be wrong?
Cheers
Posting the answer here from the comment section.
Agreed. The best way to do this is to call the following API:
_versionContext.AddRelatedObject(versionTreeEntry, "PluginStates", state);
Thanks
Pratik
I'm having trouble querying RavenDB with even the simplest of queries, probably I'm doing something wrong, but after a few hours I just can't see it anymore. I've googled almost anything I can think of..
I have these entities:
public class User
{
public string Id { get; set; }
public string DisplayName { get; set; }
public string RealName { get; set; }
public string Email { get; set; }
public string PictureUri { get; set; }
public List<Comment> Comments { get; set; }
public List<Role> Roles { get; set; }
}
public class NewsItem
{
public string Id { get; set; }
public string Title { get; set; }
public string Text { get; set; }
public DateTime Created { get; set; }
public string UserId { get; set; }
public List<Tag> Tags { get; set; }
public List<Comment> Comments { get; set; }
public List<WebImage> Images { get; set; }
}
I want to query these so I get a list of newsItems, but with the user information alongside it. So I read the docs and tried the LoadDocument feature, the index:
public class NewsItemIndexWithComments : AbstractIndexCreationTask<NewsItem, NewsItemIndexWithComments.Result>
{
public class Result
{
public string AuthorName { get; set; }
}
public NewsItemIndexWithComments()
{
Map = newsItems => from newsItem in newsItems
select new
{
AuthorName = LoadDocument<User>(newsItem.UserId).DisplayName
};
}
}
Which I try to use like:
var result = _documentSession.Query<NewsItemIndexWithComments.Result, NewsItemIndexWithComments>().AsProjection<NewsItemIndexWithComments.Result>().ToList();
Now I get the number of documents in my list, but the AuthorName is always null. If I don't use the AsProjection method, I won't get any results. Can anyone show me a proper example on which I can experiment further?
Thanks.
_ edit:
That helped a lot, thanks :) Now for step two, I'm sorry if I'm being a bit newbish, but you'll have to start somewhere. In the newsitems there are comments, in these comments there is another reference to the userid. You can probably guess what I want to do: I want the user info for the comments with the comments as well.
new Index:
public class NewsItemIndexWithComments : AbstractIndexCreationTask<NewsItem, NewsItemIndexWithComments.Result>
{
public class Result : NewsItem
{
public string AuthorName { get; set; }
public string AuthorId { get; set; }
}
public NewsItemIndexWithComments()
{
Map = newsItems => from newsItem in newsItems
let user = LoadDocument<User>(newsItem.UserId)
select new
{
AuthorName = user.DisplayName,
AuthorId = user.Id,
};
Store(x => x.AuthorName, FieldStorage.Yes);
Store(x => x.AuthorId, FieldStorage.Yes);
}
}
Comment class:
public class Comment
{
public string Id { get; set; }
public string Text { get; set; }
public string UserId { get; set; }
public string User { get; set; }
public DateTime Created { get; set; }
}
How can I query the comments and expand the results for that? Or is it better to create a new index just for the comments and get the user info analog to the solution above?
You're almost there, you just need to store the field you are projecting. Add this to the index constructor, after the map.
Store(x=> x.AuthorName, FieldStorage.Yes);
This is because you want it returned and available for AsProjection to find. If you just wanted to use the author name in a where or orderby, you wouldn't need it.
If you just want to include the comments in your AsProjection, you can simply index the entire object along.
Note that indexing a custom object will mean that you're not able to query on it using a .Where(). RavenDB can only query on flattened results (ints, decimals, strings, dates).
In order to, for instance, query on the title, you will need to create a seperate Property public string Title { get; set; } and map it with Title = newsItem.Title.
public class NewsItemIndexWithComments : AbstractIndexCreationTask<NewsItem, NewsItemIndexWithComments.Result>
{
public class Result : NewsItem
{
public string AuthorName { get; set; }
public string AuthorId { get; set; }
public List<Comment> Comments { get; set; }
}
public NewsItemIndexWithComments()
{
Map = newsItems => from newsItem in newsItems
let user = LoadDocument<User>(newsItem.UserId)
select new
{
AuthorName = user.DisplayName,
AuthorId = user.Id,
Comments = newsItem.Comments.
};
Store(x => x.AuthorName, FieldStorage.Yes);
Store(x => x.AuthorId, FieldStorage.Yes);
Store(x => x.Comments, FieldStorage.Yes);
}
}
In this website, users can register under a username and password, and can also post comments on articles. The models are pretty straightforward:
public class User
{
public int Id { get; set; }
public string Username { get; set; }
public string Password { get; set; }
public bool IsAdmin { get; set; }
public DateTime JoinDate { get; set; }
public string AvatarPath { get; set; }
public string EmailAddress { get; set; }
}
public class ArticleComment
{
public int Id { get; set; }
public int ArticleId { get; set; }
public int UserId { get; set; }
public string CommenterName { get; set; }
public string Message { get; set; }
public DateTime CommentDate { get; set; }
public User User { get; set; }
}
Entity Framework correctly made the foreign key relationship between UserId on ArticleComment and Id on User when the database was created using code-first.
Here's my code for when a user posts a new comment:
public JsonResult SubmitComment(int articleId, string comment)
{
var response = new JsonResponse();
var currentUser = _userRepository.GetUserByUsername(User.Identity.Name);
//...
var newComment = new ArticleComment
{
ArticleId = articleId,
CommentDate = DateTime.Now,
CommenterName = currentUser.Username,
UserId = currentUser.Id,
User = currentUser,
Message = comment,
};
try
{
_articleRepository.Insert(newComment);
}
catch (Exception e)
{
response.Success = false;
response.AddError("newComment", "Sorry, we could not add your comment. Server error: " + e.Message);
return Json(response);
}
response.Success = true;
response.Value = newComment;
return Json(response);
}
The values that make up the newComment object all appear to be correct, and the Insert method in my Article repository class is straight and to the point:
public void Insert(ArticleComment input)
{
DataContext.ArticleComments.Add(input);
DataContext.SaveChanges();
}
But once this happens, poof: a new record in my Users table appears along with the new record in ArticleComments. All of the info in the new Users record is duplicated from that user's existing record - the only difference is the value for the primary key Id. What gives?
In addition to my comment, you need to make sure that both _userRepository and _articleRepository are using the same DbContext instance.
Either that, or you can try this:
var newComment = new ArticleComment
{
ArticleId = articleId,
CommentDate = DateTime.Now,
CommenterName = currentUser.Username,
UserId = currentUser.Id,
// User = currentUser, let the UserId figure out the User, don't set it yourself.
Message = comment,
};