entity-framework

How to translate ObjectStateEntry.OriginalValues into Entity?

How to translate ObjectStateEntry.OriginalValues into Entity? I thought I can do this with ObjectContext.Translate method but I have to pass DataReader instead. Is there any ways? ...

Creating a list of .Include() in linq to entities

I have a long list of includes: .Include("x") .Include("y") .Include("z") .Include("z.w") .Include("z.v") I would like to use this list on three different queries. How can I put these in a list and use that list in all my queries in order to not repeat myself. ...

entity framework v4 and wpf

Hi, need some help or some advice with entity framework v4. As you already know, EF v4 does not support lazy loading of scalar properties. If i have some entity object for example Order in model with many scalar properties, some of them expensive to load from DB, like attached file for example. As i found later, it is possible to move t...

Getting Entity Framework Error: Invalid object name 'Navigation'.

I have an Entity Object called Navigation stored in a Database called Navigations. When I save the Entity calling context.SaveChanges(); I get the error Invalid object name 'Navigation'. I have removed the model and added it back in but with no change. Does anyone have any ideas? ...

ASP.Net MVC Repository Question

I have 4 different models that I'm pulling information from for a grid in a view. This code excerpt is apart of my controller for my Index action. Each Model has a repository, partRepository, parts_comboRepository, vendor_partRepository, and manufacturer_partRepository, and i use those repositories to grab data for my joins. ...

EF. Delete entity by Id that has foreign key

I have two tables Job (Id, Title) and Employee (Id, Name, JobId). 1-* relationship. How can I delete Employee that has reference to it's job without retrieving information from the database? I can do something like that: var j = new Job { Id = 1 }; // UGLY, I have to create and attach Job instance and job.Id should be exactly the sa...

WCF Data Service, serialize additional properties on from Entity Framework partial classes

I'm on the process of creating an API in much the same way Hanselman showed it could be done for Stackoverflow. I have a bunch EntityObject Entity Framework generated classes and a DataService thingy to serialize them to Atom and JSON. I would like to expose some generated properties via the web service. Think FullName as generated by co...

Namespace cannot be resolved after setting Model's Code Generation Strategy property to 'None'

I created my Entity Model in a class library project and added references to this project from other projects in my solution.I generated POCOs from the Model. All is good so far. I added a WCF service application to this solution and referenced the data model project. The data model project, named "DataModel", is now unresolved and I ge...

Entity Framework: How to properly handle exceptions that occur due to SQL constraints

Hi all I use Entity Framework to access my SQL data. I have some constraints in the database schema and I wonder how to handle exceptions that are caused by these constraints. As example, I get the following exception in a case where two users try to add an (almost) identical entity to the DB concurrently. System.Data.UpdateException ...

EF model already sets up validation on entity properties?

I've just ran into an unexpected behaviour for Entity framework entities in use with ASP.NET MVC application with SQL Server as datastore. For a column marked as not null allowed I did not set up data annotation Required attribute inside the entities' metadata partial class (I was under impression that I had to for all properties that I ...

Filetering data with WebControls and EF 4

Hi, I am trying to filter some data for a GridView Controls using a DropDownList Control. I am using EntityDataSource from EF 4 to query the Conceptual Model. I am not able to visualize in GridView my data when selecting the DropDownList (Where Entity SQL), nothing happen in the page and only the DropDownList show /( the GridView(. I d...

What's the benefit of using another model with Entity Framework in DDD

When looking at some application designs for DDD, I see that the objectgenerated from the entity framework are only used to access the data store. Once the data is loaded it's mapped to another POCO object defined in the model of the application. Is this just good design and is done for the sake of design? Or is there some added value ...

Entity Framework - Validation (server + clientside, jquery) with data annotations, WITHOUT MVC?

Hi, there are several tutorials that explain how to use EF data annotation for forms validation using the MVC framework. And to use jquery for the client side. See e.g.: http://dotnetaddict.dotnetdevelopersjournal.com/clientvalidation_mvc2.htm I would like to achieve the same, but without using MVC/MVC2. I want to build a classic asp...

Asp.net MVC 2 relation without Foreign Key with Entity Framework 4 Or With Foreign Key

1 - Is it necessary to have foreign key to obtain a Relation in Entity Framework between each entity.? 2 - I have a Language Table and many many table with a foreign key related to the language table. Is it right to add this foreign key or I should do something else ? Ex: Language LangID LangName TableTextA TblAID TextInfo Lan...

Best work around to fix DateTimeOffset over WCF Data Service issue

I try to create a WCF Data Service for an Entity Framework model, which contains some attributes of type DateTimeOffeset. However the WCF Data Service does not support the type DateTimeOffset as I found out after googling the exception text "The property 'CreationTime' on type 'Task' is of type 'DateTimeOffset' which is not a supported p...

Only update actually updated fields in Entity Framework

Quite a common use case, it seems, is when re-populating an object from a form is to go myobj.Name = "textbox value"; myobj.Content = "textbox content"; 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, regardle...

Entity Framework SaveChanges issue

Hello. I am doing some testing with EF and i was trying to get a hook on the ObjectContext.SavingChanges. Everything works when i add objects directly to their set in the context. But when i add them through an Entity nav property they don't show up in the event. I'll show an example to make it more clear. This is the method registered...

binding gridview with my getall method - entity framework

Ok please excuse my references to the gridview. So i have this method in a class called getall() what this does is gets the collection of entites from entity framework model for a specfic table, checks to see whether the table exists and then does the query using linq (linq to entities). This does work as I have used a breakpoint and ev...

ASP.NET MVC & Entity Framework: How to render a custom Model in a View ?

Hi, I have two tables Category 1..* Advertisement. I want to get the advertisements Count for each category. To do so, I use that query: var catList = (from c in DB.Category.Include("Advertisement") select new { c.Name, c.Advertisement.Count } ).ToList(); How to access the e.g the first element's p...

What is the best database architecture to use for my asp.net site?

I am looking into creating a new website using ASP.NET 4.0. I am currently starting to build a site that will need to store reporting information. My database has around 25-30 tables (with a lot of relationships) to which my web application will need to store and read information from. Normally, the architecture I use is the Layered Arc...