I am tring to learn linq to sql (and programing in general). I have created my CRUD stored procedures and dragged and dropped them from my db to dbml. Now how do I use the methods that were created?
View 3 RepliesI 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 am struggling to create a webservice method using LINQ technology and to populate a dropdown in a form. Here is the Webservice code.
[WebMethod]
public
string[] GetAllCountries()
{
LinqClassesDataContext db =
new
LinqClassesDataContext();
var q =
from c
in db.ListContinents()select
c;
return q.ToList() ;
}
And here is the form code behind
protectedvoid
Page_Load(object sender,
EventArgs e)
{
WSClass WS =
new
WSClass();//bool
ds = WS.GetAllCountries();
var v = WS.GetAllCountries();
ddlContinent.DataSource = v;
ddlContinent.DataBind();
}
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]
have following method which returns "List"
public List<DistributionGroup> GetDistributionGroupsByUserId(Guid userId)
{
return (from dgu in db.DistributionGroup_Users where dgu.UserId == userId select
[code]...
I'm really new to ASP.Net and for a school project we have to create a login form. Now I have managed to create a login with LINQ doing the following:
[Code]....
And in my html page:
protected void Test_Click(object sender, EventArgs e)
{
if (Class1.Controle(Convert.ToInt32(txt1.Text), txt2.Text))
[Code]....
I was thinking something amongst those lines, but I can't call p.GebruikerWachtwoord. So I'm guessing this is completely wrong.I hope somebody can help me figure this out, and I apologise for the poor explanation, English isn't my native language.
I have a test web service called: MySimpleService.svc with a method called:GetUserNamesByInitials. below is the Linq to SQL code:
[OperationContract]
public static string GetUserNamesByInitials(string initials)
{
string result = ""; [code]...
what I do is to type the user id in one textbox (TextBox3) and when I press the Tab key the result is shown in another textbox(TextBox4).
The jQuery call works well with other methods that do not call the database, for example using this other web service method it works:
[OperationContract] public string ParameterizedConnectionTest(string word)
{
return string.Format("You entered the word: {0}", word);
}
However with the Linq method it just does not work.
I've been scratching my head for what seems like ages. I'm sure its really simple to fix but I can't see it.
I have a class in App_Code that uses a bit of Linq.
var siteMap = SiteMapWrapper.BuildSiteMap(true);
var currentTopLevelParent = siteMap.Single(s => s.IsActive);
if (currentTopLevelParent != null)
I've developed this locally and all works fine. When I transfer to IIS hosting the same class fails to compile. I receive:
does not contain a definition for 'Single' and no extension method 'Single' accepting a first argument of type 'SiteMapWrapper' could be found (are you missing a using directive or an assembly reference?)
I confirmed that the virtual dir is running .NET 2.0 as it should. I also confirmed that the correct assemblies are being loaded in the web.config.
<compilation debug="true">
<assemblies>
<add assembly="System.Core, Version=3.5.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>
<add assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
<add assembly="System.Xml.Linq, Version=3.5.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>
<add assembly="System.Data.DataSetExtensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>
</assemblies>
</compilation>
I want to access the data from datatable object. When i trying to get the fieldslist usng "Field" method. But I could not find the method with my table object. Eventhoguh i forcibly write a method and trying to access the fields, It is giving the below error for the first join in query. Rest of the lines are fine.
What is the reason behind it.
The errro: "Error 2 'LINQ2DB.SP_VS_OP' does not contain a definition for 'Field' and the best extension method overload 'System.Data.DataRowExtensions.Field<T>(System.Data.DataRow, string)' has some invalid arguments"
What is the meaningof the error. Shall i do any other changes in the query line?
var QueryChnl = from oSPOP in SPOP.AsEnumerable()
join oDiscChannel in DiscChannel.AsEnumerable() on oSPOP.Field<int>("spid") equals oDiscChannel.Field<int>("SPID")
join oChannel in Channel.AsEnumerable() on oDiscChannel.Field<int>("channel") equals oChannel.Field<int>("channelID")
where oSPOP.Mappingkey == 3200004
select new { oSPOP.Mappingkey, oChannel.channel, oDiscChannel.STATUS };
It seem to me that this was hard...
[code].....
I get this run time error "no supported translation to SQL".
What i want is to get lists of the posts, and do a small quick calculations of the rating and then sort those from highest to low and take 5 posts only.
I have a telerik grid bound to a Linq data object, however, I limit the fields returned:
<IQueryable>filter = data.Select(x => new {x.ID, x.Name, x.Age});
I would like to access these fields in the ItemCreated method of the grid:
protected void rgPeople_ItemCreated(object sender, GridItemEventArgs e)
{
Telerik.Web.UI.GridDataItem item = (GridDataItem)e.Item;
?????? Person = (???????)e.Item.DataItem;
}
What do I declare ?? as so that I can use:
String ID = Person.ID;
String Name = Person.Name; etc
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 = ""
I'm trying to follow the demo from this link to add a jqGrid to an MVC app.
I have a table named Companies that I'm trying to display in a grid. A Company simply contains an ID and a Name.
I'm running into an error in my controller function:
public JsonResult DynamicGridData(string sortIndex, string sortOrder, int page, int rows)
{
int pageIndex = Convert.ToInt32(page) - 1;
int pageSize = rows;
var companies = companiesRepository.Companies.OrderBy(sortIndex + " " + sortOrder).Skip(pageIndex * pageSize).Take(pageSize);
//Error here
...
}
I'm getting an error on the line that is calling OrderBy():
The type arguments for method 'System.Linq.Enumerable.OrderBy(System.Collections.Generic.IEnumerable, System.Func)' cannot be inferred from the usage. Try specifying the type arguments explicitly.
I really have no idea what the error means, and I haven't been able to find an explanation. I'm not sure what is causing this error on a simple OrderBy function.
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.**
View 1 RepliesI 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 can I get it to work?
I have a query that gives me the average number of days between 2 dates in the database. It gives an error saying line does not reconize the subtract method. What is the best way to do this, i prefere not to have to get the whole table as a list and loop though.
Using em As EE.EclipseEntities = New EE.EclipseEntities
Return em.OrderLines.Where(Function(w) w.Received_Factory_On.HasValue) _
.Average(Function(a) CDate(a.Received_Factory_On).Subtract(CDate(a.Sent_Factory_On)).Days)
End Using
I am using LINQ and sending a linq object to the view and trying to show it in a textbox like this
<%=Html.TextBox("petname",Model.PetName) %>
But I am getting error, how can I show (PetRecord.PetName) which is my linq entity
I have an ObjectDataSource that I want to perform updates using a business entity i.e. Type="Object"). Since the values for the entity are within a user control, I have stored a reference to the control in Session and in the updating event, set the new instance to the value of the entity from the user contol property (which also pulls values from the form viaother properties of the control):
Protected Sub MasterDataSource_Updating(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.ObjectDataSourceMethodEventArgs) Handles MasterDataSource.Updating
Dim entity As New Login()
Dim accountControl As AccountInfo = TryCast(Session("AccountCtrl"), AccountInfo)
entity = accountControl.Entity
e.InputParameters.Add("entity", entity)
End Sub
And here's the markup for the datasource:
<asp:ObjectDataSource ID="MasterDataSource" runat="server" EnableCaching="true" CacheDuration="10"
SelectMethod="SelectAll" UpdateMethod="Update" TypeName="Data.DAL.LoginDAL">
</asp:ObjectDataSource>
My question is, how can I get the update method to pass this entity to the update method in my BLL class? It seems the Update method requires an ID or reference to the original object to use in determining whether any changes have taken place, but I don't really want to do this. In other words, I just want to use the Update event on my ObjectDataSource to pass my entity to the method ("Update") I set as a property and then let this business method handle the update of the data. Shown below, is the BLL update method I want to call:
Public Overloads Function Update(ByVal entity As Login)
If entity Is Nothing Then
Throw New ArgumentNullException("entity")
End If
MyBase.Update("UpdateLogin", entity.Username, entity.Password, entity.FirstName, entity.LastName, entity.Role, entity.Region, _
entity.Email, entity.Title, entity.TierID, entity.Street, entity.City, entity.State, entity.Zip, entity.Mobile, entity.Phone, entity.Fax)
End Function
When I try to call this as it stands now, I get an error: ObjectDataSource 'MasterDataSource' could not find a non-generic method 'Update' that has parameters: ID, entity. Previously, I'd set up a long list of parameters of basic data types (string, int, boolean), but this is rather cumbersome and I was hoping to use an entity for this (FYI, I also got the same type of error when I tried this approach, but with the ID as the
last parameter in the list). Perhaps what I'm doing here is atypical to how the ODS is normally used?? Has anyone done something like this successfully?
I have an application that has JS calling ASMX files to do asyncronous requests, using ASP.NET AJAX.
The problem is that I use always the same "onError" function, and now I don't know how to identify the method that rised the error, and it is giving me a lot of problems to debug errors. The parameter "data" of the onError method does not give enough information, for
example:
en System.ComponentModel.BaseNumberConverter.ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, Object value)
en System.Web.Script.Serialization.ObjectConverter.ConvertObjectToTypeInternal(Object o, Type type, JavaScriptSerializer serializer, Boolean throwOnError, Object& convertedObject)
en System.Web.Script.Serialization.ObjectConverter.ConvertObjectToTypeMain(Object o, Type type, JavaScriptSerializer serializer, Boolean throwOnError, Object& convertedObject)
en System.Web.Script.Serialization.ObjectConverter.ConvertObjectToType(Object o, Type type, JavaScriptSerializer serializer)
en System.Web.Script.Services.WebServiceMethodData.StrongTypeParameters(IDictionary`2 rawParams)
en System.Web.Script.Services.WebServiceMethodData.CallMethodFromRawParams(Object target, IDictionary`2 parameters)
en System.Web.Script.Services.RestHandler.InvokeMethod(HttpContext context, WebServiceMethodData methodData, IDictionary`2 rawParams)
en System.Web.Script.Services.RestHandler.ExecuteWebServiceCall(HttpContext context, WebServiceMethodData methodData)
Is there any way to know the webmethod that raised the error?
I don't know what I'm making wrong.I have a submit button, and on click it should execute the funktion in the code behind, but I get the error that the funktion is undefined.this is my code in the .aspx webform:
<%@ Page Language="C#" AutoEventWireup="True" MasterPageFile="~/DashMaster.master" CodeBehind="BI_MDR.aspx.cs" Inherits ="BI_MDR.StoredProc"%> [code].......
I want to create a web method that accepts a List of custom objects (passed in via jQuery/JSON). When I run the website locally everything seems to work. jQuery and ASP.NET and everyone is happy. But when I put it on one of our servers it blows up. jQuery gets a 500 error after the ajax request with the response being:
System.InvalidOperationException: EditCustomObjects Web Service method name is not valid.
[WebMethod]
public void EditCustomObjects(int ID, List<CustomObject> CustomObjectList)
[code]...
I have seen 2 methods to handle error in project. One is using try catch in every method and another is using custom page and error log file .I know both method. Which one is the best method?
View 9 RepliesI have a DetailsView control about a store products.
When I hit the "Edit" button of the DetailsView control, I want to bind a DropDownList to list products categories and select the current product category in it.
I used the method "ModeChanged" to select the current product category like this:
[Code]....
the FindControl method DOES NOT find the "ddlCategory" (returns null) although it's present in the EditTemplateField.
I'm thinking to use "DropDownList's PreRender" event for doing the purpose I aim, but I want to know what is wrong!
How to solve this error? Error message is "BC30289: Statement cannot appear within a method body. End of method assumed.".
View 1 Replies