I have some questions regarding the entities framework. Once you create your DataModel, if later you modify it such as removing fields adding tables it is possible for the EF to auto detect changes or you have to refresh it manually? If you have to refresh it.. how do you refresh it to reflect new changes? Also do it affect in any way the data in the database?
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How would one go about detecting a page refresh / F5 key push on the controller handling the postback? I need to distinguish between the user pressing one of two buttons (e.g., Next, Previous) and when the F5 / page refresh occurs.My scenario is a single wizard page that has different content shown between each invocation of the user pressing the "Next" or "Previous" buttons. The error that I am running into is when the user refreshes the page / presses the F5 key, the browser re-sends the request back to the controller, which is handled as a post-back and the FormCollection type is used to look for the "submitButton" key and obtain its value (e.g., "Next," "Send"). This part was modeled after the post by Dylan Beattie at http://stackoverflow.com/questions/442704/how-do-you-handle-multiple-submit-buttons-in-asp-net-mvc-framework.Maybe I'm trying to bend MVC 2 to where it isn't meant to go but I'd like to stay with the current design in that the underlying database drives the content and order of what is shown. This allows us to add new content into the database without modifying the code the displays the content.
View 1 RepliesI am using Request.Browser.IsMobileDevice in conjunction with the MDBF file that goes in the App_Browsers/Devices folder [URL] Now using Sea Monkey browser (latest version 2.0.7) IsMobileDevice returns true. Why might this be the case as clearly Sea Monkey is not a mobile browser. In fact, I had the understanding it used a lot of the same core as FireFox (which does not return true)
View 2 RepliesMy setup is this; first I'm defining a couple of new rows.
newCompany = new company
companyInfo = value.company_info,
companyName = value.company_name,
organizationNumber = value.company_orgnr
[code]...
I use the ObjectDataSource in an ASP.NET Application.
Using the ASPxGridView. When Updating it goes back to the Data Access Layer and tries to update the Entity, now as I can see while having some properites (Columns, Visible = false) when the entity arrives in the update method the visible = false columns have no values.
I don't want to show all the columns...what if I need 3 of the 30 columns? So I thought I would get the original entity from the context and merge the differences from the updated entity.
I am currently trialing EF4 code-first. My POCO classes inherit from an Audit class that contains CreatedBy, CreatedOn, UpdatedBy, UpdatedOn. I was hoping the framework would include the Audit properties in my Action table when creating my database, however this doesn't appear to be the case. Does anyone know how to enable this without overriding the OnModelCreating() method?
Public Class Audit
Public Property CreatedOn as DateTime
End Class
Public Class Action
inherits Audit
Public Property ActionId As Int32
End Class
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.
View 5 RepliesI just want to know what are the main differences between ADO.NET Entities Framework and LINK to SQL ? It is okay to use ADO.NET EF for a simple website ? What advantages each have?
View 3 RepliesI have a Consumer class and a BillableConsumer : Consumer class. When trying to do any operation on my "Consumers" set, I get the error message "Object mapping could not be found for Type with identity Models.BillableConsumer.
From the CSDL:
[code]....
Is this because I did not specifically add the BillableConsumer entity to the object set? How do I do that in a POCO scenario?
Could anyone tell me where is the best place to put my business methods when using EF4 code first POCOs? Should they go in the POCO class? E.g.
public class customer
public property Id as int32
public property Name as string
public property Archived as boolean
public sub MarkAsArchived
me.Archived = true
end sub
public function EmailAllInvoices as boolean
...
end function
end class
Or should the POCO class be as clean as possible and a seperate class be used for business logic which accepts an instance of a customer POCO in the constructor to work on?
I am sort of new to Entities Framework however I have successfully built a complete CMS website with the Entities Framework 4.0 in MVC 2.0 following the design patterns and examples laid out in nerddinner and MusicStore.
I am now building another application in ASP.NET webforms however would still like to flex the ORM capabilities of ADO.Net Entity Framework 4.0 however found that it seems like I am always forced to use Entity ObjectDataSource to bind to a GridView etc...
I know I might sound silly to some however I need a few pointers on creating this ASP.NET web application to use Entity Framework and use something like the design pattern of Dependency Injection etc... and still able to bind to GridViews programmatically in code behind.
I like the seperation of using a ntiers design but also would like to have full code control and not be forced to use ObjectDataSources in my aspx page.
Due to the way the database was designed, in my model I have a User entity. The Contact entity inherits from the user entity, and the Profile entity inherits from the Contact entity.
How can I get a list of Profiles, and, how do I create a Profile?
let us assume that I have a reusable business layer that further makes use of a data access layer that was implemented using Entity Framework 4.0. The entities returned/consumed by the business layer are self-tracking, allowing us all the goodies that come with those type of entities. I would like to be able to store the entities I work with across post backs (on order to avoid re-querying every time). Basically let us assume I have a paged GridView with 10 items in it, and something like a DetailsView to edit those items. Every time you select a new row on the grid, the details view updates with the information of the selected row. My preference would be to only query for the entities on the initial request of the page and store it in session. Then subsequently I have a list of entities that I can work with and eventually modify and send back to the business layer with all of the changes.
I really want to use session instead of view state to reduce the page payload (self tracking entities are heavy) however I really like view state for this because of the fact that when the user navigates away from the page there is no residual effect. Some of the things that worry me are: When a user navigates away from the page to another page, the entities from the previous page are still in session. I could always do something on load of a page to do housekeeping type of work. Not sure if that's good practice. I am worried about people opening browser tabs and having two views into the same page, it seems like that might pose a problem. Is this even a good approach? Seems like I am trying to have the best of all worlds, it would definitely be much easier to simply re-query on every post back for the entities and pay the 50-100ms hit of the database trip.
I have a model that consists of Order, OrderLine, Product.
I want to create an Order and add OrderLines (each OrderLine related to a Product). I create the Order and add new OrderLines to it. Between posts I store the Order entity in Session (or ViewState). Just so you know I have added suppport for binary serialisation which works fine.
The relationship is therefore Order > OrderLine(s) > Product(s).
You might have already guessed what the problem is - that when I SaveChanges() I get the usual 'AcceptChanges cannot continue because the object's key values conflict with another object in the ObjectStateManager.' error.
I have referred to a number of articles online but none seem to handle this case (where I have the relationship across more than two entities) e.g. [URL].
This must be a very common requirement surely? Is there anyone out there doing the same kind of thing with Entity Framework (and without using DTOs etc)?
I am trying to get some guidance with this issue:
I have a Customer object that has two address ID fields (one for HomeAddress and one for WorkAddress)
I am loading the Address Objects by using Include="HomeAddress, WorkAddress" and then binding to the properties using the Navigation Property on the Customer Entity
Can I use just one FormView for doing the Insert/Updates and binding it to an EntityDataSource or would I have to do all the Inserting/Updating manually?
Using a very run-of-the-mill database, with identity int for primary keys, a Dynamic Data Entities Project (EntityFramework) displays the primary key for view and edit. When using Linq to Sql, the primary key fields are not displayed.
I would like to hide the primary keys and use Entity Framework (VS 2008, .Net 3.5 sp1).
I created two stored procedures in SQL Server Management Studio.
First procedure add field in ProjcetsToUsers table (for many-to-many associations)
[code]....
I can delete the user from the project and then add another, and the new one is added but removed the remains.
As for data base both this function work correctly.
DbClick the code behind file of NerdDiner.edmx,It reads "This code was generated from a template." on the top comment lines. I generate my own .edmx file automatically with VS2010, just found that the .designer.cs file didnt contains Objectset,Methods as nerddinner does IDK which template hanselman used to generate this .edmx files，dont tell me he wrote it all by himself! Shoud .edmx and its code behind file be generated automaticlly without hard-coding?
View 4 RepliesWhen I refresh the entity framework with big table, I get the System.OutOfMemoryException.
Is there any better way to refresh the EF with big tables? I'm using .Net 3.5
I ran into this problem using EF4 and a self-referential table (implementing an adjacency list hierarchy). NOTE: not a many-to-many reference, just a one-to-many on a single table. Attempts to resolve an intermittent InvalidOperationException ("...The ObjectContext might be in an inconsistent state...") using Context.Refresh fail due to an apparent bug in EF4. I saw, from following Shimmy's connect.microsoft.com link, on the aforementioned post, that the bug is still outstanding. Can anyone recommend a workaround? What do you do if your database and Entity Framework get out of sync?
When I get the InvalidOperationException and the message says "The changes to the database were committed successfully...", it is not true. They weren't. I tried to change an object's ParentId from 1 to null (ParentId of type int?). My object's ParentId attribute is correctly changed to the expected value (null). I call Context.SaveChanges(). Then, the exception is thrown. I check the DB, and the value has not been updated. In this case, ParentId is still 1 in the database...................
I have a datamodel with a couple of tables. One of my tables have about 40 fields (I know that is a lot, but we have to keep the structure in place as we are upgrading a classic ASP project to MVC). Some of my Actions only updates 1 or 2 fields in my table.
Is there a way to create Entities, for instance, that only contains the contact details of the client table, and not any other details, and then another entity that contains only the address details. I don't want to submit the entire row when I only update telephone details, or the client's picture.
We are starting a new web based product in which we are planning to expose our business logic through WCF services. We will be using ASP.NET 4.0, C#, EF 4.0. In future we want to build iphone applications and WPF applications based on the services. I have been reading a lot about using POCO vs Self Tracking Entities (STE) and from my understand the STEs do not work well with the web scenario.
View 3 RepliesIn my JavaScript I'm trying to redirect to third party page. It can open a page either in a new window or inside a frame depends on a user settings. Something like this:
if (newWindow)
{
window.open(url, targer);
}
else
{
theFrame = url;
}
What I want to do is to display my custom page in case a third party site is down or page is unavailable. Basically in case of 404 error.
I googled this topic and I came across with three different ways to configure browser capabilities: browscap.ini, browserCaps element in web.config and .browser files in App_Browsers. I thought .browser files is the latest way, but I don't seem to find up-to-date files. But I found quite fresh browscap.ini from [URL]
My first priority is to exclude common crawlers from the visitor stats. The second priority is to detect browser and os with correct versions (e.g. Opera 11 / Win7). Are there any libraries I could use? Is browscap.ini still a valid way and is it possible to use it without access to system files? Where can I find up-to-date .browser files?
I need to separate IE and FF browsers from others it's a pseudo-code :
If (CurrentBrowser == IE(6+) or FF(2+) )
{
...
}
else
{
...
}
in protected void Page_Load() event (think so)
if ((Request.Browser.Type == "IE") || (Request.Browser.Type == "FF"))
{
WebMsgBox.Show("1111");
}
no effects :-/ what is IE and FF types?
