DataSource Controls :: LINQ Doesn't Reference Data Context In ListView?
Feb 7, 2010
I'm trying to add a LINQ datasource to my ListView control but it doesn't pick up the data context that I created. All it shows as options in the dropdown list are AJAX objects. What could be the possible causes for this?
I have downloaded Visual Web Developer 2010 Express and am trying to use LINQ. In order to do that I have added a LINQ to SQL class to the web site and have dragged tables from the database view into the LINQ designer, which worked fine.But..When I add: using System.Data.Linq;to MainPage.xaml.cs, I receive an error:
Error 3 The type or namespace name 'Data' does not exist in the namespace 'System' (are you missing an assembly reference?)Even although I have references to System.Core, System.Data, System.Data.Linq in the website references.
I lifted some nice code to handle memberships, but I want to add a customer specific field. My issue is how to reference my class from the inline c# code.
[Code]....
The problem is the line csUserProperties.AddNew(intUserId, lngCustomerId); -- I get the error "The name 'csUserProperties' does not exist in the current context. I have <%@ Import Namespace="csUserProperties" %> at the top of the file. I also tried everything with no namespace in the class below.
I'm currently trying to work out the best way to build this web application, which will then be intergrated on other systems, such as WinForms, Intranets etc.
We hope to include the usual layers i.e. DAL, BLL, BOL and UI but I have been experimenting with Entity Framework 4 and WCF Data Services and managed to get something in place where I was using WCF as a gateway to EF4.
i.e. Adding a Service Reference to my project and then using the EF4 context and writing LINQ queries against the DB
e.g.[Code]....
Now with the current setup I would still need to write a DAL Class Library, that interacts with the Data Service, because as I said WCF Data Services only seems to be a gateway, I can't see where to put the code (above) in the Data Service and then how I could these methods.
My questions are: 1. How do I develop a WCF Data Service in such a way to allow this behaviour - I know how I could do it using ASMX web service, something like [Code]....
2. If I am to use WCF Data Services, how is serialization handled (if at all) - again I know how to do something in ASMX web services
3. Again, If I am to use WCF, how do I add Security and only allow my applications to access the web service - for obvious reasons
4. Would it be possible / logical to also include the Business Logic Layer into the web service?
I have something like the following in pages in two different projects, which saves to a DB with a LINQ to SQL operation:
[Code]....
One of the pages works with this code and the other doesn't. The only difference is that the project in which it does work employs a data control tool (ListView) and a custom profile provider.
I have a Listview with a LinqDataSource. I am allocating a resoure called Bladder Scanners to clinicians on the day selected. The field in the database, 'Allocated_Bladder_Scanner_Id', allows nulls. The 'nullable' property of the field in the dbml is set to allow nulls.In the edit template, I have an unbound dropdownlist (drpBladderScannerDropdown) with an 'empty string' item added to cater for nulls, and AppendDataBoundItems="true".In order to show only bladder scanners which have not yet been allocated on the selected day, I am databinding the dropdownlist to a dictionary of unallocated bladder scanners in the ItemDataBound event. I then add the currently selected bladder scanner as a listitem and set it as the selected item. So far, so good, all works well. However, if the clinician has a bladder scanner currently allocated, and then the user elects to not allocate the clinician a bladder scanner on that day by selecting 'Nothing' from the dropdownlist, the LinqDataSource fails to update the field. It does not throw an exception, it just doesn't set the field to nulls. In ItemUpdating I have the following code:
I am working on asp.net 3.5 and in MVC using Linq to SQL classes. In my MVC project i am calling stored procedure using linq to sql that conatin query joining two tables.Below is my code in Partial class
[ Function(Name="dbo.GetUserWiseThreadDetail_SP")] [ResultType(typeof(Thread))] [ResultType(typeof(Reply))] public IMultipleResults GetUserWiseThreadDetail_SP([Parameter(DbType="VarChar(30)")] string userID) { ExecuteResult result = this.ExecuteMethodCall(this, (MethodInfo)(MethodInfo.GetCurrentMethod())), userID); return ((IMultipleResults)(result.ReturnValue)); }
In one of the controller i have made one more class
public class MypostIndexData { public IEnumerable<Thread> Thrds { get; set; } public IEnumerable<Reply> Repls { get; set; } public MypostIndexData(IEnumerable<Thread> thrds,IEnumerable<Reply> repls) { this.Thrds=thrds;this.Repls=repls; } }
finally coding of controller action method
ForumDataContext pmforum = new PMForumDataContext(); public ActionResult MyPosts(string userId) { IEnumerable<Thread>thrds; IEnumerable<Reply>repls; IMultipleResults result = pmforum.GetUserWiseThreadDetail_SP(userId); (this satement doesnot give any result,if i execute stored proc in sql it give the results) thrds = result.GetResult<Thread>(); List<Thread> thrdlist = new List<Thread>(thrds); repls = result.GetResult<Reply>(); List<Reply> replylist; if (repls != null) { replylist = new List<Reply>(repls); } return View(new MypostIndexData(thrds,repls));
I am unable to understand why i am not getting any results?
I am trying to populate the ListView using LinqDataSource data source but the issue I am having is.I need to load the listview on Search button click action.
IN the page_load I kept like this: =========================================== LinqDS.Selecting += new EventHandler<LinqDataSourceSelectEventArgs>(LinqDS_Selecting);
protected void LinqDS_Selecting(object sender, LinqDataSourceSelectEventArgs e) { e.Result = ObjectDS; } ============================================= This works fine but this happens on page load,i want this binding to happen on button click?is there a way to do this?
I keep getting Object Reference not set to an instance of an object errors when I try to use the ListView delete function. It is a fairly freshly created listview and is very close to the original template so not sure what is going wrong. Some possibly relevant code:
[Code]....
I also put in a breakpoint in the deleting event (only reason I added the deleting event) to look at the status of everything. When I do: Contact delContact = (Contact)e.Entity; and look at the values, the values for almost everything are set to null. It does have the correct value for the ID of the contact object that needs to be deleted. When I continue to step, it jumps to my designer.cs file and appears to break here:
[Code]....
likely because _Case_ID is null. The exact exception I'm encountering is: System.NullReferenceException: Object reference not set to an instance of an object. While I could probably re populate the object with correct values, that doesn't seem likely to address the real cause of the problem.
I'm having trouble writing what should be a simple sub-query using LINQ to Entities. I have two tables: Customers and Orders that have a relation on the CustID field. Not all Customers have a record in the Orders table, while some have mutiple records. In traditional SQL, you could write the query like this: SELECT * FROM Orders where CustID IN (SELECT CustID FROM Customers) I know this could be done as a JOIN in both SQL and L2E, but my actual query is more complex (about 8-9 joins), so I am hoping to find a L2E sub-query equivalent. Something like this:
[Code]....
I know LINQ to Entities does not support the " IN " clause, so I am looking for something that will work in its place.
I'm trying to check dynamically generated "checkbox" value inside Listview.
I can reference non-dynamic checkboxes exact in same location (index) inside Listview using "e.Item.FindControl", however I can't reference dynamic checkboxes.
For some reason my DataContext is not showing all the normal methods like SubmitChanges() etc in the intellisense.It also won't compile if I type in db.SubmitChanges();Any idea what I'm doing wrong? Normally I don't have this issue, I have several other projects that work fine...
I'm trying to delete a item from the listview. I can delete the item from the database ok, but the listview item does not get removed, I could do a Response.Redirect to redisply the page but this is overkill? Below is my code:
No data is loaded when the button (btnSearchWrd) is clicked. Instead, in the Firefox Error console, it listed these two errors:Error: item is undefinedError: ys.WebForms.PageRequestManagerServerErrorException: Could not determine a MetaTable. A MetaTable could not be determined for the data source '' and one could not be inferred from the request URL. Make sure that the table is mapped to the dats source or that the data source is configured with a valid context type and table name, or that the request is part of a registered DynamicDataRoute.
I have a problem with using the listview.When I want to update or cancel the update, the listview doesn't leave the edit mode.When I clicked the updatebutton, the methode Listview.Itemupdating is fire and changes the database. But then nothing happened. Even if i set the itemindex -1.The Listview.Itemupdated does also not fire.This is the code.
I am building a WCF Web Service that has a Business Logic layer (that implements all validation logic and other business rules) and a Data Access Layer that makes calls to Stored Procedures in my database.
I would like to be able to validate the length of data passed against that of the length of the parameters in the Stored Procedures without having to explicitly define the parameter lengths in my WCF Web Service.
Eg:
Person Object Person.Name = "John Dhoe" Person.Age = 37 SQL Stored Procedure SavePerson FullName Varchar(15) Age Int
In my BLL or DAL, I would like to be able to do something like :
I need a Listview that will show info from several database tables. My delete button, will not delete the record from the database. I cannot get DeleteOnSubmit() to work at all. I am in the very beginner stage. This is my first project. I thought this would be a good project for learning purposes.
I've got a ListView with a DataPager on one page and then a FormView with the items detailson another page. There is an Image in the ListView where the user can click on the image andthat takes them through to the page with FormView on it.If the user goes through to the FormView page and then press's back on the browser to takethem back to the page with the ListView on if the user then click's on the DataPager it takes