C# - Best Way To Edit And Update Complex Viewmodel Objects Using Mvc2 And Entity Framework?
Apr 2, 2010
I have a table in my database with a one to many relationship to another table, which has a relationship to a third table:
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This seems to work fine. My question to you good folks: Is there a correct way to do this? I tried following the making a custom model binder per the blog link I posted above but it didn't work (there was an issue with reflection, the code expected certain properties to exist) and I needed to get something going ASAP. PS - I tried to cleanup the code to hide specific information, so beware I may have hosed something up.
I'm trying to use formview in order to do insert of a new entity object (called Customer) Customer has a reference to another entity called Address. How can I fill both of them in the same formview?
I want to be able to update a model and all its collections of child objects in the same view. I have been referred to these examples: http://haacked.com/archive/2008/10/23/model-binding-to-a-list.aspx and http://blog.stevensanderson.com/2010/01/28/editing-a-variable-length-list-aspnet-mvc-2-style/ .
For example, I have an object Consultant, that has a collection of "WorkExperiences". All this is in an Entity Framework model. In the view, the simple properties of the Consultant object is no problem, but the collection I cannot get a textbox to show up for. I tried following the examples in the links above, but it doesn't work. The problem is, in those examples the model is just a list (not an object with a child list property). And also, the model again is an EF model. And for some reason that doesn't seem to work as in those examples.
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This stuff with the EditorTemplate works fine in Phil Haack's sample project, which I downloaded to try, but here, with the EF model or whatever the problem is, I don't get any textbox at all. The table in the view is just there as a test, because in the table I do get the rows for WorkExperiences, whether I add an empty WorkExperience object or fill out its properties doesn't matter, the rows show up for each object. But again, no textbox...
getting data from multiple Entities models into an MVC controller. Most of the examples I have seen for using EF in an MVC2 app only use a single entitiy.
I have just started using MVC2 in C# using the Entity Framework models (CIOps.model) created from an SQL database. I can create the controller and views using single tables of the model in MVC2, but I just cannot get my head around how to get data from multiple entity tables into the controller (similar to joins in T-SQL). I have included an example below of the controller code that works with a single entity table, tbl_tours (tbl_tour in DB).
Could someone please illustrate how this code would be changed to include additional columns from FK tables in addition to tbl_tours columns. E.g. the clients name from the tbl_clients, the coordinators name from the tbl_employees, and costs from tbl_costs entities? Is it possible to do this directly using the EF model entities/classes that are already created and not use LINQ, POCO, Repositories, etc.? The FK relationships are already in the EF models. I have included the whole controller code, but I just need a few examples of how to join the multiple entities, not rewrite every CRUD function function in the controller. I think this will get me over the hump in using EF in an MVC2 App. Also ignore the fact I am using the home controller, this will change in the application.
[HttpPost] public ActionResult Edit(int id, FormCollection fc) { Movie movie = ( from m in _ctx.Movie.Include("MovieActors") where m.MovieID == id select m ).First(); MovieActorViewModel movieActor = new MovieActorViewModel(movie); if (TryUpdateModel(movieActor)) { _ctx.ApplyPropertyChanges(movieActor.Movie.EntityKey.EntitySetName, movieActor.Movie); _ctx.SaveChanges(); } return View(movieActor); }
However, I am not sure how to test this, and in general would much rather have the method take a typed model like:[HttpPost] public ActionResult Edit(MovieActorViewModel movieActor) Is this possible? What changes to my MovieActorViewModel class do I need to make in order to enable this? That class looks like this:
public class MovieActorViewModel { public Movie Movie { get; set; } public Actor Actor { get; set; } public PublisherDealViewModel(Movie movie) { this.Movie = movie; this.Actor = ( from a in this.Movie.Actors where a.ActorID == 1 select a ).First(); } }
The view is typed (inherits ViewPage) simple:
<% using (Html.BeginForm()) {%> Movie Title: <%= Html.TextBoxFor(model=>model.Movie.Title) %><br/> Actor Name: <%= Html.TextBoxFor(model=>model.Actor.Name) %> <% } %>
If I have Database Stored Procedure retrun Complex type (Contain from Columns for 2 tables) ( Composite) and No Relation between them so i can't use Navigation Property ... so how can I use That in ADO.NET Framework specially when i try to use Add Function Import i didn't find any thing else None, Scalars, Entites.
I've been tasked to convert our old DAL that have gen objects to possibly the Entity Framework 4.0. We create objects inheriting from our genned objects and have a ton methods our legacy codes uses. Does anyone have an idea or possible solution on how to create an entity framework model that maps to our old genned objects? Or a solution that requires us to modify our legacy code minimally?
I am using Entity Framework for my .NET application. I have been able to return objects and their directly-related objects as well (very convenient), but I am having trouble getting the objects of those objects.
IEnumerable<Lot> i = (((ObjectSet<Car>)_carRepository.GetQuery()) .Include(a => a.CarTypes).Take(10).ToList()
This works and I can access carTypes, however I cannot figure out how to access tables associated with CarTypes (e.g. tables which have fields associated with the car types). I tried to use a Join however I was unable to figure out how to get it to work right.
I have an EDM, it includes the entities extension and history. My goal is to use history to keep track of all the changes made to extension entity. For example, if extension with ID 223 has its property 'Name_Display' changed - I want the history entity to record this.
I'm using ASP.NET with VB.NET. Where in my code do I put the hook to say, "update the history entity" and what should that hook look like?
I am mapping a stored procedure to an entity by right clicking on the entity (in the .edmx) and selecting "Stored Procedure Mapping." This brings you to a Mapping Details - "Name of Entity" Window that allows you to select the insert, update, and delete stored procedures associated with the Entity. It also maps the stored procedure parameter to the Entity "Property" (Column).
I'm gettin an error "error 2042: Parameter Mapping specified is not valid." The cause of the error is fairly obvious, in the Insert stored procedure that has been selected, a 'CHAR' parameter is being mapped to an Int32 Entity Property. I altered the stored procedure parameter to match the entity, I deleted the stored procedure, readded, and reslected it as the Insert function. I also cleaned, validated, updated model from database. No matter what I do, the parameter list in the mapping details doesn't reflect the change to the stored procedure. It's stuck on a char --> int32 mapping, even though it has been changed, like it's buried deep in meta data some where.
I have a question, much liket this unanswered one. I'm trying to work with the entity framework, and having a tough time getting my foreign tables to update. I have something basically like this in the DB:
Incident (table):
-ID -other fields
Responses (table):
-FK:Incident.ID -other fields
And and entities that match:
Incident (entity) -ID -Other fields -Responses (EntityCollection of Responses via navigation property)
Each Incident can have 0 or more responses.
In my Webpage, I have a form to allow the user to enter all the details of an Incident, including a list of responses. I can add everything to the database when a new Incident is created, however I'm having difficulty with editing the Incident.
When the page loads for edit, I populate the form and then store the responses in the viewstate. When the user changes the list of responses (adds one, deletes one or edits one). I store this back into the viewstate. Then when the user clicks the save button, I'd like to save the changes to the Incident and the Responses back to the DB. I cannot figure out how to get the responses from the detached viewstate into the Incident object so that they can be updated together.
Currently when the user clicks save, I'm getting the Incident to edit from the db, making changes to the Incident's fields and then saving it back to the DB. However I can't figure out how to have the detached list of responses from the viewstate attach to the Incident. I have tried the following without success:
Clearning the Incident.Responses collection and adding the ones from the viewstate back in:
Incident.Responses.Clear() for each objResponse in Viewstate("Responses") Incident.Responses.add(objResponse) next Creating an EntityCollection from my list and then assiging that to the Incident.Responses Incident.Responses = EntityCollectionFromViewstateList Iterating through the responses in Incident.Response and assigning the corresponding object from viewstate: for each ObjResponse in Incident.Responses objResponse = objCorrespondingModifedResonseFromViewState Next
These all fail, I'd like to be able to merge the changes into the Inicdent object so that when the BLL calls SaveChanges on the changes to both the Incident and Responses will happen at the same time.
We have an ASP.NET MVC site that uses Entity Framework abstractions with Repository and UnitOfWork patterns. What I'm wondering is how others have implemented navigation of complex object graphs with these patterns. Let me give an example from one of our controllers:
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It's a registration process and pretty much everything hangs off the POCO class Person. In this case we're caching the person through the registration process. I've now started implementing the latter part of the registration process which requires access to data deeper in the object graph. Specifically DPA data which hangs off Legal inside Country.
The code above is just mapping out the model information into a simpler format for the ViewModel. My question is do you consider this fairly deep navigation of the graph good practice or would you abstract out the retrieval of the objects further down the graph into repositories?
I'm writing a custom .NET MembershipProvider (not the built in one) and trying to update using Entity Framework. But of course i have no access to (Try)UpdateModel. How can i update it?
I have an entity generated from my database that contains one table. When i make changes in the DB i obviously would like these changes to reflected in my model.
My current approach is to delete the item from the designer and then right-click - update model from database. This works for me at the moment. Is there a different approach to refreshing these entity tables ?
I have been updating my Entity Framework by simply right clicking and clicking on "update model from database". I usually go under the "Add" tab and then click the tables and click finish. I also use "refresh" sometimes as well. What are the differences between these? and also when I do refresh or add sometimes the entity comes out wrong or keeps some of the old information in cache, how can I just get the entity to match my database and clean out any of the old cached things.
I have a few entities I'd like to update at the same time. However I'd like to write individual update methods in each classes partial class file, for each entity and call them all at the same time. For example:
public sub UpdateEntity1() ... end sub
public sub UpdateEntity2() ... end sub
public sub UpdateEntity3() ... end sub
public sub UpdateAll() UpdateEntity1() UpdateEntity2() UpdateEntity3() end sub
My question is how do I manage the object context? do I create one object context in the class I'm calling UpdateAll(), then pass it as a parameter to each individual update method? Or do I create a new context for each Update? I'd like to use the same context because the object are related, and this would decrease the db calls to update all the records.
I'm making an MVC2 app to manage billing schemes. These billing schemes can be of various types, e.g. daily, weekly, monthly, etc. and all types have their specific properties. My class structure looks like this:
public abstract class BillingScheme { /* basic billing scheme properties */ } public class BillingSchemeMonthly : BillingScheme { public string SpecificMonths; } //etc. for other scheme types
I retrieve a billing scheme through the base class using the billing scheme ID, and it gives me an object of the correct type. The property SpecificMonths maps to a database varchar field that contains a ;-separated string of month numbers. I want to split this to an array so I can create a list of checkboxes and I'd preferably do this with a facade property in a viewmodel. I could do it right inside the view but that seems to go against the MVC pattern.
The problem is I can only create this viewmodel specifically for a BillingSchemeMonthly, and I can't cast a BillingSchemeMonthly to a BillingSchemeMonthlyViewModel. I'd rather not implement a clone method in the viewmodel since the entire billing scheme is quite large and the number of properties may grow.
But, name may not have changed, it may only be a change to the content textbox.
The problem is that entity framework treats Name as changed just because I've set it's value, regardless of whether I've set exactly the same value or not.
Ideally, I would like EF to only mark things as changed if they genuinely have changed.
How should I solve simulation update, when one user updates already updated entery by another user?
First user request 'Category' entityobject, second user does the same. Second user updates this object and first user updates. I have field timestamp field in database that wa set to Concurrency Mode - Fixed.
How do I use a stored procedure to change one or more (but not all) fields of a entity in EF4? I have a stored procedure "ChangePassword" taking a username and and a password as parameters and a User entity containing properties for Username and Password as well as other properties. I want to be able to use this stored procedure from a function to update the password from a function in one of my repositories. How to do this?
I have read some articles about the new enitity framework and I think it looks very cool from a development perspective.
considering a production environment loaded with data. How does one apply changes to the model? You cannot regenerate the model and in most large organizations, database changes are executed by DBS's and not developers. In such situaitons, it is the role of the developer to develop delta-scripts that the dba can execute.
My experiense with Hibernate (Java) and the like is that you have to pay double when using such frameworks.
I have a webservice which of course has to be .net 3.5 (a side note is does anyone know why you can't create a webservice using .net 4.0?).
Anyhow it is using entity framework, which I have recently discovered was a really bad mistake to try to use this in .net 3.5.
I have a table "Licenses" with the following columns: LicenseKey, ProductCode, OrderID, Seq, UserName.
In my asp.net 4.0 application I can simply do the following to perform an update:
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But it appears there is no ExecuteStoreCommand in .net 3.5 with entity framework. Can anyone explain to me how to accomplish the same thing? The thing I need to point out is that because this is a multi-user access service. I need to verify that SQL will only update the given record where OrderID and Seq is what I tell it ONLY if the UserName is already null. So if two users process the same statement at the same time only one would work and the other would not because the sql should fail (or return 0, rather than a 1) for the second one.
