ADO.NET :: Contains() Method Not Working In Linq To Entities
Mar 8, 2011
I am building a web application in asp.Net 4.0 and entity framework. I am trying to retrieve a list of products based on a collection of id's. I first gather all the id's in a collection and then pass it to the linq query. I am trying to get a functionality similar to the IN clause in SQL. The problem seems to be with the Contains() method in the Linq to entities query. Here is my Linq code:
[Code]....
I got the above Linq to entities method from here: [URL]
I am creating an Asp.net web site which will support dynamic data. When I am creating a dynamic web site from Scratch (from template in VS) all is working fine. But when I am trying to add dynamic entity (.edmx) file and running the application I am getting following error
"The method 'Skip' is only supported for sorted input in LINQ to Entities. The method 'OrderBy' must be called before the method 'Skip'. "
I mean, what is the faster way to get as fast as I can more than one table with stored procedure? Is there any study what is faster and why? There is a big problem getting more than one table at once with Entities, so the only way is DataSet. But I was told DataSet work very slow. Is that true?
I have a GridView and on a row being deleted I trigger the GridView1_RowDeleting sub, but I receive an error "LINQ to Entities does not recognize the method 'System.Web.UI.WebControls.TableCell get_Item(Int32)' method, and this method cannot be translated into a store expression." Code is:
Private Sub GridView1_RowDeleting(sender As Object, e As System.Web.UI.WebControls.GridViewDeleteEventArgs) Handles GridView1.RowDeleting ' The deletion of the individual row is automatically handled by the GridView. Dim dbDelete As New pbu_housingEntities ' Remove individual from the bed. Dim remove_bed = From p In dbDelete.Beds _ Where p.occupant = GridView1.Rows(e.RowIndex).Cells(3).Text _ Where p.room = GridView1.Rows(e.RowIndex).Cells(6).Text _ Where p.building = GridView1.Rows(e.RowIndex).Cells(5).Text _ Order By p.id Descending _ Select p remove_bed.First.occupant = "" dbDelete.SaveChanges() ' Increase number of open spaces in room. Dim update_occupancy = From p In dbDelete.Rooms _ Where p.room1 = GridView1.Rows(e.RowIndex).Cells(6).Text Where p.building = GridView1.Rows(e.RowIndex).Cells(5).Text _ Select p update_occupancy.First.current_occupancy = update_occupancy.First.current_occupancy - 1 dbDelete.SaveChanges() End Sub
The specific line erroring out is: remove_bed.First.occupant = ""
Im my MVC 3.0 Application, I created a helper like below;
[Code]....
And I used that helper in a linq query as below;
[Code]....
When I fire my app, it gives me the below error. LINQ to Entities does not recognize the method 'System.String GenerateURl(System.String)' method, and this method cannot be translated into a store expression. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.NotSupportedException: LINQ to Entities does not recognize the method 'System.String GenerateURl(System.String)' method, and this method cannot be translated into a store expression. Source Error:
Line 43: public Blogs GetBlog(string urlstring) { Line 44: Line 45: return GetAll().SingleOrDefault(x => BlogUrlGeneration.GenerateURl(x.ArticleTitle).Equals(urlstring)); Line 46: } Line 47:
Ä°n my blog, the link will be like below; [URL] so I need to set the above urlgenerator class into lambada. How can I do that? What would it take to make that work perfectly
When i use the query **var NewMatchs = (from x in entity.matches select x).LastOrDefault();** I got error like this **LINQ to Entities does not recognize the method 'SocialSports.Models.match LastOrDefault[match](System.Linq.IQueryable`1[SocialSports.Models.match])' method, and this method cannot be translated into a store expression.**
I am using Entity Framework to contact my data base. as part of my web code I am using Linq to entities, and I want to determine the number of elements in an anonymous type list. I can't get it to work, I get the exception: "LINQ to Entities does not recognize the method 'Int32 Parse(System.String)' method, and this method cannot be translated into a store expression."
var questItem = from chapters in context.TestChapter from questions in context.Question where chapters.ID == int.Parse(Request.QueryString["id"]) where questions.TestChapterID == chapters.ID select questions.ID; int numOfSteps = questItem.Count();
How to use Stored Procedures with Linq to Entities? I prefer an example with input and output The videos on asp.net only show how to do this with Linq to SQL.
SELECT * FROM MessageAlerts AS A LEFT OUTER JOIN Contacts AS C ON A.ContactId = C.Id LEFT OUTER JOIN Users AS U ON A.UserId = U.Id INNER JOIN Businesses AS B ON B.Id = C.BusinessId OR B.UserId = U.Id
how to do this : ON B.Id = C.BusinessId OR B.UserId = U.Id with linq in entity framework.
WHY are all the examples on this site linq to SQL? Did ms not themselves announce dropping support for l2SQL over a year ago? i really don't get it. Examples are great.. but really not helping me since i've gone ahead and listened to MS. And can someone at MS clarify what the position is for linq 2 SQL.. Is it supported? Recommended? What the hell.
I am trying to learn LINQ to entities, and am working out how to best structure my BLL layer. I have generated the entity model and have created a generic repository in my DAL that returns results as IList<T>. I initially created the BLL to also return
results as IList<T>:
public IList<DAL.Customer> SelectAll() { [code]...
Now I am working on the aspx page, and I can create an ObjectDataSource and configure it to use my BLL, but since I am returning IList, I can't sort since I am not using a DataView. I have seen some articles on the web for converting IList to DataView, but that seems like a lot of overhead for every query.My goal is to keep a clean separation between layers without making things overly complicated. I would like to know how others have done this, or maybe a link to a good tutorial that shows how to structure all three layers.
I have a message table that self joins to itself where Message.ID == Message.Parent. So I have 1 Message with several ChildMessages. This is set up nicely with a Navigation property.
The code is currently:
var message = from m in soe.Messages.Include("ChildMessages") where m.ID == id && m.IsActive select m; return message.FirstOrDefault();
What I really want is to only return 1 Message (that is equal to a particular ID and isActive) with all of its Active ChildMessages and I want to do it in one call to the database.
i have a table with a field name called 'Firstname' and another field name called 'Lastname'. I would want to have a single column in my GridView which show Fullname and then the firstname and lastname are showed here under an alias. Also, i am binding my GridView using LINQ.So is there a way to create aliaswith LINQ and to use these with GridView ? Would love to have an hint about how i can realize this task.
I use the Entity Framework and Linq to Entities with MVC 2.0. When use the DropDownListFor from Html helpers to populate a dropdown that contains an ID from a foreign object, I post the form data but I can´t set the correct relation. Using the debug, I can see the ID retrieved from dropdown at my returned foreign object ID, but I think that I not use the association correctly.
have already used the latest technology in a professional manner. NETBasically I have two tables related 1 to 1:the Users table and the table ProfiloPersonale is the key to the Users table that this table are ProfiloPersonale iduser and type uniqueidentifier and diagram sql server 2008 I can clearly see the report, I also did a test to insert a record in the users table ( fictional) directly from sql server and everything works.With LINQ to Entities does not work:The entities 'LEntities.Users' part of the eport 'ProfiloPersonale'.Found 'ProfiloPersonale' related to 0.Expected 1 'ProfiloPersonale'Of course what I am doing is to first create the user and then create their profile in the db, taking the id of the registered
I have a view on my database and I am trying to add a new record using the AddTo method but it is not working. I noticed that LinqToEntities is creating the insert statement like this
Insert into (select field1, field2 from my_view) (field1, field2) values (value1, value2)
Is it possible to make LinqToEntities create the insert statement like the one below ?
Insert into my_view (field1, field2) values (value1, value2)
All I am trying to do is query the database, then get the returned values, so that I can do some calculations. But, I don't understand how to get the values from the database row that is returned, so that I can assign it for usage.
I would like to do something where the logic goes: for the index of [1] (which is just column 1), multiply it by 2. For the index of [2] (which is just column 2), multiply it by 3.
In the code bdehind && syntax does not work, any ideas?
Entities ctx3 = new Entities(); var uniqueQuote = from quot in ctx3.Quotes.Include("aspnet_Users").Include("Enquiries") where quot.Enquiries.EnquiryId == selectedEnquiryId && [code]...
Error 2 Delegate 'System.Func' does not take '1' arguments C:LocalGarageFinderLocalGarageFinderEnquiryDetail.aspx.cs 56 33 LocalGarageFinder
I am use the new ASP.NET MVC 2 and Entity Framework, but when I try to create a new view with strongly-typed option selected, the entity objects is not appears at dropdown and I cannot use the view creation wizard. I recompile the solution, but still not appears yet. Have any workaround that I forgot to do to enable the entities to be displayed at dropdownlist ?
I am working on a website similar to nerddinner. Is it possible to perform similar join using Linq to entities what is done with linq to sql in nerddinner.I am posting the codes below.
public IQueryable<Dinner> FindByLocation(float latitude, float longitude) { var dinners = from dinner in FindUpcomingDinners() join i in db.NearestDinners(latitude, longitude)
