I 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 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 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.
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?
View 2 RepliesDue 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?
What is the difference, if any, between letting the framework do the modelbinding to a parameter:
[Code]....
vs. invoking the modelbindng manually/explicitly in the action method:
[Code]....
Is there any difference(s)? E.g., does the framework use the parameter name (m) during the modelbinding in the former method in some way that it might not do in the latter way?
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 RepliesI 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.
I am trying to download MVC framework but it doesn't work.
View 4 RepliesWe 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 opinion, these architectures have some differences, such as:
1. 3-layer is a linear architecture, but MVC is a triangle architecture.
2. Presentation Layer of 3-layer includes View and Controller of MVC? And Model of MVC includes Business Layer and Data Access Layer of 3-layer
I think 2 differences above are not obvious or are incorrect!
Are there any major differences between the ASP.NET Cache Class from ASP.NET 3.5 to 4.0?
View 2 Repliesin one of the application i have been reffering connection string is stored in appsettings! till now i have been storeing the connection in <connectionstring/> element. But, what is the correct way?
So my quetion is, What is the differences between <connectionstring> and <appsettings> in web.config, are there any specific reason why i should or should not be storing connection string in appsettings? Are there any rules / guidlines provided to follow? Or is this completely the choice of the developer?
What are the differences between aspx and jspx? and Why should I choose aspx or jspx?
what is the best software to develop web poject with jspx?
What's your opinion of the following job interview question?In the requirement it never mentions about to have classic ASP experience.
But the question is "What are the differences between ADO.NET DataSet and ADO Record Set?".
I think that I am confuse here. Now I am using WebParts as they being used on 2.0 framework (like they are using on TheBeerHouse kit)
But in most of the forums they talk about SharePoint. Does sharepoint means webparts as I know them, or this is a new version of the webparts?