Retrieving Data Is Slow Only When Use Entity Framework In The Code Page?

Aug 20, 2010

When I use classical ADO.NET or (which is interesting) EntityDataSource (e.g. for GridView), then page load within 1 second.But when I use ic codefile code like:

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Cty = CType(Request.QueryString("cty"), Integer) ' course type
Page.SetFocus(ddl_FGPhotosOK)
If Not IsPostBack Then ' read course status
Using ctx_sdbEntities As New sdbEntities()
[code]...

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Cast Exception When Try To Insert Entity In Entity Framework (using Code-f)

Feb 9, 2011

I get an cast exception when i am trying to insert an entity in Entity Framework (using code-first). From this code :

public virtual T Insert(T entity)
{
return Context.Set<T>().Add(entity);
}

The cast exception is like "impossible to cast ...Collection'1(Entity) to type (Entity)" I can't figure out why. I am pretty sure ive done everything right. Post entity

public class Post
{
public long PostId { get; private set; }
public DateTime date { get; set; }
[Required]
public string Subject { get; set; }
public User User { get; set; }
public Category Category { get; set; }
[Required]
public string Body { get; set; }
public virtual ICollection<Tag> Tags { get; private set; }
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Category = new Category();
if (Tags == null)
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Oct 25, 2010

Is there a way to export a EF 4.0 Data Model to EF 3.5?

I looked around and found that we are not able to access EF 4.0 from a ASP.Net 3.5 project here: [URL]

Our project is the 1st to go to .Net 4.0 using Entity Framework and we (the team) were wondering if there was a way for the other projects that "might" need to access our data that are still using the .Net 3.5 framework.

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Pattern For Retrieving Complex Object Graphs With Repository Pattern With Entity Framework

Oct 13, 2010

We have an ASP.NET MVC site that uses Entity Framework abstractions with Repository and UnitOfWork patterns. What I'm wondering is how others have implemented navigation of complex object graphs with these patterns. Let me give an example from one of our controllers:

[code]....

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ADO.NET :: Entity Framework Code First For Print Shop

Feb 14, 2011

I have a good friend who owns a print shop and he has asked me to create him a simple online shop where he can take print orders. His print shop location is kind of hidden, and business isn't going well at the moment. This is why he wants to move online. I said I would do it for him, but it will take a while before he has anything to look at. Where I am most stuck is the Model. The problem with this sorts of shops is that each Product, depending on its category would have different attributes. How ? Here is an example: [URL] A user would choose a product category, then he/she would get to the following: [URL] Now he/she would click the Order link to order a certain qunatity. On the next page, depending on what category they are in, they'll get a form where they can choose order attributes. There aren't many attribues for BUSINESS CARDS. But if they had chosen CARBONLESS FORMS, they would get options to tweak like: Squencial Numbering to start from 103490Position of Numbering..etc

I asked for advice at the SQL Server forums, and finally I came up with something like this:[URL] But with that database design, I will have a lot of type casting to do for the attributes ! << In fact I'm not sure if that would be even possible. Then I watched this video, and the author does something cool ! she uses Inheritance. Then I started Wonding ... Is it possible for me to have a Parent [ Product ] class, and have its children entities with different (added) attributes?

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Perform Relationships In Entity Framework 4 Code-First CTP 5 ?

Jan 19, 2011

I would like to have a short example on how do you actually perform relationships in Entity Framework 4 Code-First CTP 5 ?

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* one-to-many
* many-to-many

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ADO.NET :: Cascade Delete - Same Table - Entity Framework 4 Code First

Feb 8, 2011

I been looking but I cant find any info on this topic Anyway I got a model that looks like this.

[Code]....

I want to cascade delete a category with all its sub categories but I cant make that reference in the database, not with the option to cascade update or delete. It work fine with pagecontents and all the other I got its just this same table reference. In NHibernate I do the cascade setting hbm or with a better way using the fluent option. How do I go about this task now?

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MVC 3 Application Using Ninject, Entity Framework 4 Code-First CTP 5, Patterns

Jan 24, 2011

ive tried to build some base project with above technologies. I wanted maximum flexibility and testability so i tried to use patterns along the way to make this as a base for future projects. However, it seem.something is wrong or whatever and i really need help here. So

i have two questions :1- Is there anything wrong with my current code ? Ive applied patterns correctly ?

2- Why do this code actually connect to the database, create it, but doesnt support insert even if i perform the corrects operation ? (Look at the end of the post for details about this error)

I have two entities : Comment and Review

COMMENT [Code]....

REVIEW[Code].... I built up a base repository for each of them this way :GENERIC REPOSITORY[Code]...For specific operations, i use an interface :[Code]....So i am getting the generics operations from the abstract class plus the specific operations :[Code]....As you figured out, i also use a database factory will produce the database context :DATABASE FACTORY [Code]....DISPOSABLE (Some extensions methods...)[Code]....DATABASE [Code]....And to finish, i have my unit of work....UNIT OF WORK[Code]....I also binded using Ninject the interfaces :NINJECT CONTROLLER FACTORY [Code]....however, when i call in the constructor ...[Code]....

This seem to create the database but doesnt't insert anything in the database in EF4. It seem that i may figured out the problem.. while looking at the database object.. the connection state is closed and server version throw an exception of this kind :

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I am doing the right things ? Is there anything wrong in what ive built ? Also if you have recommandation about the code i posted, i would be glad. I am just trying to the learn the right way for building any kind of application in MVC 3. I want a good a start.

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[Code]....

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Im a fan of the EF code first and with its last preview of the CTP5 I wonder if it would be safe for me to use this for a smaller site for customer? I would love to get your opinions on this? And any good sources for tutorials and information would be sweet. I'm currently reading the post on scottgu's blog about it.

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Entity Framework CTP5 - Code First - Many To Many Relationship With Cascade Delete

Jan 4, 2011

I have two entities (Customer and CustomerRole) and would like to declare many-to-many relationship between them. I can do using the following code:

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Entity Framework CTP5 - Code First - Nested Query Error

Jan 3, 2011

I have the following classes:

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this.Property(c => c.Name).IsRequired().HasMaxLength(400);
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{
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{
}
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{
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I am new to entity framework , it is really very good , but I want to know what is the difference between using entity framework with stored procedure or without stored procedure , which one the faster and what is the benefits for using stored procedures with entity framework.

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Entity Framework -Update Entity When Another Entity Is Updated

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Eg. If my ID is 1056, then in my DataGridView in Page2.aspx should populate elements of this ID.

This is the code:

protected void Page_Load(object sender, EventArgs e)
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Error While Updating Database Record With Entity Framework On MVC Page?

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I have an ASP.NET Page that updates registered User Address Details for a selected record.

Below is the Update method that i am calling from Controller.

When i am calling ApplyPropertyChanges method, I am getting the below error.

Did anyone run into the same error while updating the record with Entity Framework.

[code]...

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ADO.NET :: Entity Framework - Entity Stored Procedure Mapping - Can't Update

Feb 10, 2011

I am mapping a stored procedure to an entity by right clicking on the entity (in the .edmx) and selecting "Stored Procedure Mapping." This brings you to a Mapping Details - "Name of Entity" Window that allows you to select the insert, update, and delete stored procedures associated with the Entity. It also maps the stored procedure parameter to the Entity "Property" (Column).

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ADO.NET :: Entity Framework Copy Entity And Change PK And Save Old And New

Mar 31, 2011

I have a stupid problem with the Entity Framework. I get the following Exception:

[Code]....

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User : varchar(20)
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I am using the following code in VS2005:

[Code]....

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I have a textbox that I need to make sure the case is right. I am using the code below but it is very slow, plus when I close my web page I get an error.

[Code]....

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