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:

modelBuilder.Entity<CustomerRole>()
.HasMany(cr => cr.Customers)
.WithMany(c => c.CustomerRoles)
.Map(m => m.ToTable("Customer_CustomerRole_Mapping"));

But it creates the relationship (and the third mapping table) with cascade delete switched off by default. How can I tell EF to create the relationship with cascade delete switched on when using many-to-many?

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[Code]....

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Entity Framework CTP5 - Code First - Nested Query Error

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I have the following classes:

public class Category
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public int CategoryId { get; set; }
public string Name { get; set; }
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Entity Framework - One To One Relationship - Save Record?

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I have a one-to-one relationship on two tables with are represented by 2 classes in my EDM. I am trying to save a new record and am confused how to save to the second entity. I have tried the following.

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DataSource Controls :: Entity Framework Deleting Many To Many Relationship?

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I have 3 tables User, role and UserInRole THe entity frame work made entities for User and Role and I have successfully made a join with the user and role entities using user.add(role); but I can't seem to get it to remove the link (I want to retain the user and role just remove their association).

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The oposite worked when I did r.User.Add(u); but it wont let me now remove it after it been created. Driving me mad as I can't see where I have gone wrong.

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How To Remove / Delete 0..1 Entity In Entity Framework 4

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I have an Events table and an InstallmentPlans table. The relationship is 0..1 : an Event can have 0 or 1 Installment plans. If I want to remove the existing InstallmentPlan for an event, how do I do this? Setting it to null doesn't seem to work:

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

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Ms Entity Framework Delete Child Object

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How can i make my own delete method to prevent that the data really gets deleted? i want to set a datetime field when it gets deleted insted of a normal delete. i read about overriding the submitchanges function, but i don't get it to work

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Nov 22, 2010

How can i insert,update and delete records using entity framework data model.

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

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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]....

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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.

I use :
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- ASP.NET MVC 3
- Ninject as DI Container

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

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C# - CTP5 EF Code / Getting Error

Mar 6, 2011

You can find the source code demonstrating this issue @ http://code.google.com/p/contactsctp5/

I have three model objects. Contact,ContactInfo,ContactInfoType. Where a contact has many contactinfo's and each contactinfo is a contactinfotype. Fairly simple I guess. The problem I'm running into is when I go to edit the contact object. I pulled it from my contact repository. Then I run "UpdateModel(contact);" and it updates the object with all the values from my form. (monitoring with debug) When I save the changes though, I get the following error:

The operation failed: The relationship could not be changed because one or more of the foreign-key properties is non-nullable. When a change is made to a relationship, the related foreign-key property is set to a null value. If the foreign-key does not support null values, a new relationship must be defined, the foreign-key property must be assigned another non-null value, or the unrelated object must be deleted.

It seems like after I call update model it nulls out my references and this seems to break everything?

Here are my models:

public partial class Contact {
public Contact() {
this.ContactInformation = new HashSet<ContactInformation>();
}
public int ContactId { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public virtual ICollection<ContactInformation> ContactInformation { get; set; }
}
public partial class ContactInformation {
public int ContactInformationId { get; set; }
public int ContactId { get; set; }
public int ContactInfoTypeId { get; set; }
public string Information { get; set; }
public virtual Contact Contact { get; set; }
public virtual ContactInfoType ContactInfoType { get; set; }
}
public partial class ContactInfoType {
public ContactInfoType() {
this.ContactInformation = new HashSet<ContactInformation>();
}
public int ContactInfoTypeId { get; set; }
public string Type { get; set; }
public virtual ICollection<ContactInformation> ContactInformation { get; set; }
}

My Controller Action:

[AcceptVerbs(HttpVerbs.Post)]
public ActionResult Edit(Contact person) {
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} else {
return PartialView(person);
}
}
Context Code:

protected override void OnModelCreating(System.Data.Entity.ModelConfiguration.ModelBuilder modelBuilder) {
modelBuilder.Entity<Contact>()
.HasMany(c => c.ContactInformation)
.WithRequired()
.HasForeignKey(c => c.ContactId);
modelBuilder.Entity<ContactInfoType>()
.HasMany(c => c.ContactInformation)
.WithRequired()
.HasForeignKey(c => c.ContactInfoTypeId);
}

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ADO.NET :: Entity Framework With Stored Procedure Versus Entity Framework Without Stored Procedures

Nov 2, 2010

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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ADO.NET :: EF Code First CTP5 Not Generating The Database?

Jan 22, 2011

I've been using EF as my primary ORM for quiet some time now. Today I decided to use EF Code First to create my model for my new project. So I went ahead and read a bunch of documents on MSDN and some blog posts by Scott Guthrie and others. Unfortunately, what I've read does not go beyond the basics of using Code First within an ASP.NET MVC application. But as you might know, in real-world applications the structure of the solution is a little different. Anyway, to make a long story short:

- I created all the POCO files that will be needed.

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- I added the following connection string to my Web.config file

[Code]....

Then I started the application and checked whether a new database was created inside SQL Server 2008 Express, but found nothing. I'm not sure what's wrong but I suspect it might be the way I'm structuring my solution? Here's the structure:

- Sharwe.MVC : The ASP.NET MVC3 Web Application (has nothing except a HomeController and a corresponding simple view at the time being)

- Sharwe.Data : model class and data access logic (contains all the POCO classes and the SharweEntities class)

- Sharwe.Services : Business logic

Here's an image that shows the structure of my solution:

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Entity Framework -Update Entity When Another Entity Is Updated

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MVC :: Display Lookup Field Using EF Code First CTP5?

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I am hoping that people are not going to think it is too simple to bother with, because I am beyond stressed here..

I am trying to display a grid of Articles and their types using:
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The grid needs to look something like this:

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what I need to change/add to the following

[Code]....

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i have 2 tables which are connected with FK.

StdPErsonal_info.Pk = Sid and student.FK = Sid

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