Entity Framework 6 - Knowledge Base (KB)
6940 results
Entity Framework calculated properties
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
Am I crazy for using Entity Framework with an OleDB connection?
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
Video lessons on ASP.NET MVC, Entity Framework, and LINQ - including MIX09, PDC, and 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
In entity framework, how do you perform a "in" query?
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
Entity validation best practices in ASP.NET MVC and 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
LINQ to Entities only supports casting in the Entity Framework. basic kinds in the Entity Data Model
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 cache certain Entity Framework instances
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
When serializing an object of type 'SubSonic.Schema.DatabaseColumn,' a circular reference was discovered.
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
Detach and retain associated object graphs in Entity Framework
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
master detail / multi table best practice/method Add to 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
Navigation properties from Entity Framework TPH classes are included.
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
What is the best way to 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
SaveChanges() in Entity Framework does not retrieve the created 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
Custom properties for the 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
Is there an Entity Framework equivalent of Linq2Sql's DataContext.GetTableTEntity> (ObjectContext.CreateQueryT>)?
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
PostgreSQL entity framework
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 Object Delete Issue
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
Entity Framework issue after adding column to database 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 Make Entity Framework Queries Faster
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
Entity Framework and Views
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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