Entity Framework 6 - Knowledge Base (KB)
6940 results
Calculated properties in Entity Framework
Suppose I have an Employee object with the following properties:...string Name { get; } float Hours { get; } float Wage { get; } ...I want to add a property, Salary, which equals Hours * Wage. In an ordinary business object, I would simply code that up in...
asked by Chris B. Behrens
Entity Framework with OleDB connection - am I just plain nuts?
I'm experimenting with the Entity Framework and I want to connect to an Access 2007 database....The following code is inspired by ...http://msdn.microsoft.com/en-us/library/system.data.entityclient.entityconnection.connectionstring.aspx...I suspect that I...
asked by fran
Posttorial: ASP.NET MVC, Entity Framework and LINQ video tutorials - Including MIX09, PDC, TechED
EDIT:...During this post I started searching on video tutorials on ASP.NET MVC, EF and LINQ and found some very useful links which I shared here. As I believe videos are more interactive and easier to learn from. Hope, they'll help....Guys, pl...
asked by Ramiz Uddin
How to do an "in" query in entity framework?
How can I do a select in linq to entities to select rows with keys from a list? Something like this:...var orderKeys = new int[] { 1, 12, 306, 284, 50047}; var orders = (from order in context.Orders where (order.Key in orderKeys) ...
asked by NotDan
Best practice entity validation in ASP.NET MVC & ADO.NET Entity Framework
i am using ASP.NET MVC & ADO.NET Entity Framework in a project. I want to add validation logic to my entities via partial classes. It works similar like shown in the ...NerdDinner.com ASP.NET MVC Application... which is using LINQ2SQL. The main difference...
asked by Alexander
Entity Framework: LINQ to Entities only supports casting Entity Data Model primitive types
I wrote a method to allow for an Expression to be passed in for the orderby clause, but I ran into this problem....Unable to cast the type 'System.DateTime' to type 'System.IComparable'. LINQ to Entities only supports casting Entity Data Model pri...
asked by Programmin Tool
How to make Entity Framework cache some objects
I'm using Entity Framework....In my database are stored persons and country of their origins. When I'm loading a person object I wan't to know what is the place each person originates. Is there a way to cache list of countries so that there wouldn't be un...
asked by Eugeniu Torica
A circular reference was detected while serializing an object of type 'SubSonic.Schema .DatabaseColumn'.
I am trying to do a simple JSON return but I am having issues I have the following below....public JsonResult GetEventData() { var data = Event.Find(x => x.ID != 0); return Json(data); } ...I get a HTTP 500 with the exception as shown in the title...
asked by Jon
Entity Framework - Detach and keep related object graph
I've just started using Entity Framework rather than my normal NHiberante to see how EF works and so far I'm having lots of problems but one in particular is detaching an object and keeping the related child objects.... I bought the O'Reilly Entity Framew...
asked by Dan
best practise/way for master detail / multi table Insert in Entity Framework
My table structure is this...Orders ------ Id int identity OrderDate smalldatetime OrderStatusid tinyint Products -------- Id int identity Name varchar(50) OrderDetails ------------ Id int identity OrderId int (fkey) ProductId int (fkey) Amount decimal...
asked by Binoj Antony
Including navigation properties from Entity Framework TPH classes
I've got an EF hierarchy that (dramatically simplified) looks something like this:...class Room { EntityCollection<Session> Sessions; } class Session { EntityCollection<Whiteboard> Whiteboards; EntityReference Room; } class Whiteboard { EntityCollection<W...
asked by Ken Smith
How do I add ROW_NUMBER to a LINQ query or Entity?
I'm stumped by this easy data problem....I'm using the Entity framework and have a database of products. My results page returns a paginated list of these products. Right now my results are ordered by the number of sales of each product, so my code look...
asked by Whozumommy
Entity Framework - SaveChanges() doesn't get the generated Identity key
I'm using entities Framework in my project and it has been a nightmare!...I have a SQL DB were I have a table called Form....Form has an ID that is a PK and Identity (it's automatically increased)....This time I'm doing this:...Dim form as int32 Dim dbfor...
asked by Txugo
Adding custom property to Client Side Entity class
I need to add a custom property to an Entity Framework class, however when I do I get the "The property name XXX specified for type XXX is not valid." error. Is there some attribute I can give the property so it is ignored and not mapped to anything?...E...
asked by Sprintstar
Does the Entity Framework have an equivalent of DataContext.GetTable<TEntity> from Linq2Sql (ObjectContext.CreateQuery<T>?)
I'm looking for an equivalent of the ...DataContext.GetTable<TEntity>... in Entity Framework. I've found the ...ObjectContext.CreateQuery<T>... method but it is different from ...DataContext.GetTable<TEntity>... since it needs a querystring to work....Is ...
asked by marcob
Entity framework PostgreSQL
Can someone tell me how can I get MS Entity Framework working with PostgreSQL. ...Also: How does Entity Framewok work with Mono? Could you please suggest other similar ORM tools which would run on Mono and what is your opinion about them?
asked by Markus
Entity Framework Delete Object Problem
i am getting "The object cannot be deleted because it was not found in the ObjectStateManager". while Deleting object....here is codes ;...//first i am filling listview control. private void Form1_Load(object sender, EventArgs e) { FirebirdEn...
asked by Ibrahim AKGUN
Problem with Entity Framework after adding column to DB table
I needed to add a new NVARCHAR column to a table in my DB. So I added the column, and then fired up Visual Studio to update the EDMX-file for the Entity Framework....I ran update model from database on everything, which only resulted in "data reader is in...
asked by Marcus L
How to optimize Entity Framework Queries
I am using Linq-To-Entities to do a query which is returning only 947 rows but taking 18 seconds to run. I have done a "ToTraceString" to get the underlying sql out and ran the same thing directly on the database and get the same timing. ...I have used th...
asked by Calanus
Views and Entity Framework
I've created a view in my database which I would like to include in my entity model. However, when I try to update the entity model through VS 2008, a warning message informs me that the TABLE OR VIEW I'm trying to add doesn't have a primary key. ...It se...
asked by cepriego
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