Entity Framework 6 One To Many Relationship Add and Update Results Exceptions

Entity Framework 4 Code First demonstrates how to declare a one-to-one connection (POCO)

Using Entity Framework 4 Code First (POCO), how do you define a one-to-one relationship?...I discovered ...this inquiry (one-to-one relationships in Entity Framework 4)..., however the resource that the response cites was not helpful (there is one line of code that is a 1-1 relationship, but no mention of how to define it).

Update "one to many" relationships with separate associations using Entity Framework, Code First.

I spent much too much time trying to solve the problem in the situation below. What seemed to be a straightforward situation turned out to be somewhat challenging. The inquiry is:...How can I change the end of an existing "many to one" connection in a "detached" situation using Entity Framework 4.1 (Code First technique) and "Independent associatio...

The First One-to-One Relationship in Entity Framework

Your execution, in my opinion, is flawed. As far as I know, EF does not allow you to define a one-to-one connection in this way.... Look at your produced database; it has an...Account_Id... column that you've specified...Periods... table. What you need to define is as follows:...public class Account { public int Id { get; set; } public stri...

How do I establish a one to one relationship with Entity Framework Code First

One-to-one connections can only be used with EF on tables that have a common primary key. Your...AccountConfig... table has a foreign key to the table's own primary key....Account... . With this configuration, EF only allows one-to-many relationships....A good description of the 1:1 and 1:0..1 connections in EF may be found in ...This piece.... The...

Create one to one relationship by using entity framework database first

By coding ...EF Code Initial... as follows, we can establish a one-to-one relationship:...public class User { public int UserID {get;set;} public string Name {get;set;} public int UserDetailID {get;set;} public UserDetail Detail {get;set;} } public class UserDetail { public int UserDetailID {get;set;} public string Address {get;set:} public int U...

EF Code-First One-to-one relationship: Multiplicity is not valid in Role * in relationship

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Entity Framework Code First Fluent API configuration for one to one identifying relationship

The structure of my classes is as follows:...How can the Fluent API be set up to add an identifying relationship to the Cards table?...I mean...Table of Cards: Id and CustomerId...Table of Cards FK: CustomerId...When I assign a new Card to the Customer, I want the old one to be removed. Property of cards....The following is how I defined my classes...

Dbset<TEntity>.Add(entity) assigns an ID and this results in a exception

You can indicate whether or not the ID is assigned by the database using Identity in your fluent (and also declaratively) mapping. Your code shouldn't assign it if you state that it IS allocated since else you will get an exception. You may say it like this in fluent:...public Car { public int ID { get; set; } public string Brand {get; set...

Entity Framework - Updating entity with added/modified child and grandchild entities

Yes, you must take that action....When you complete everything inside a...DbContext... scope it takes care to keep track of all entity changes, and you don't need to do anything to inform the DbContext of the changes....However, with multi-layered systems, you cannot keep the entities inside a layer when you move them between them....DbContext... Y...

Entity framework Code First One-to-One relationship

For a 1:1 attempt, foreign keys are not supported:...public class User { [Key] public Guid Id { get; set; } public string Name { get; set; } public string Lastname { get; set; } public string Username { get; set; } public virtual UserActivation UserActivation { get; set; } } public class UserActivation { [Key] [For...