Entity Framework Nullable Foreign Key Error
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here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the workings and policies of this site About Us Learn more about Stack Overflow the company Business Learn more entity framework insert null foreign key about hiring developers or posting ads with us Stack Overflow Questions Jobs Documentation Tags Users c# entity framework nullable foreign key Badges Ask Question x Dismiss Join the Stack Overflow Community Stack Overflow is a community of 4.7 million programmers, just like you, helping each entity framework foreign key null other. Join them; it only takes a minute: Sign up How to get Entity Framework Code First and nullable foreign key properties to work? up vote 8 down vote favorite 6 I'm trying to create a simple entity
Entity Framework Nullable Foreign Key Guid
framework code first application. I have these classes: public class User { public int UserId { get; set; } public string Username { get; set; } public virtual ActivationTicket ActivationTicket { get; set; } } public class ActivationTicket { public int ActivationTicketId { get; set; } public virtual User User { get; set; } public string Ticket { get; set; } } When I try to create a new user and save it to the database (a entity framework code first nullable foreign key user without a ActivationTicket that is) I receive an exception The INSERT statement conflicted with the FOREIGN KEY constraint "ActivationTicket_User". The conflict occurred in database "Test", table "dbo.ActivatioTickets", column 'ActivationTicketId'. The statement has been terminated. I assume EF treats the mapping between User and ActivationTicket as 1-1 but it should be 1-0..1 What do I have to do to get this to work? c# .net entity-framework-4 ef-code-first share|improve this question edited Dec 20 '11 at 20:19 abatishchev 57k56214353 asked Mar 4 '11 at 4:34 b3n 1,49042339 1 "What do I have to do to get this to work?" - Make sure you throw salt over the correct shoulder. –Ian Warburton May 12 '11 at 10:11 add a comment| 2 Answers 2 active oldest votes up vote 15 down vote accepted You will need a mapping rule like this: modelBuilder .Entity
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Entity Framework Allow Null Foreign Key
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Entity Framework Foreign Key Nullable
million programmers, just like you, helping each other. Join them; it only takes a minute: Sign up Entity framework code-first null foreign key up vote 52 down vote favorite 11 I have a User < Country http://stackoverflow.com/questions/5189701/how-to-get-entity-framework-code-first-and-nullable-foreign-key-properties-to-wo model. A user belongs to a country, but may not belong to any (null foreign key). How do I set this up? When I try to insert a user with a null country, it tells me that it cannot be null. The model is as follows: public class User{ public int CountryId { get; set; } public Country Country { get; set; } } public class Country{ public List
First Next Working with Inverse Navigation Properties Close Programming Entity Framework: Code First by Julia Lerman... Published by O'Reilly Media, Inc. https://www.safaribooksonline.com/library/view/programming-entity-framework/9781449317867/ch04s02.html Programming Entity Framework: Code First SPECIAL OFFER: Upgrade this ebook with http://www.c-sharpcorner.com/uploadfile/ff2f08/entity-framework-error-the-relationship-could-not-be-chang/ O’Reilly Preface Audience Contents of This Book Conventions Used in This Book Using Code Examples Safari® Books Online How to Contact Us Acknowledgments 1. Welcome to Code First Modeling with EF Before Code First Inception of Code First Getting Code First to Developers entity framework in Between .NET Releases Writing the Code…First Managing Objects with DbContext Using the Data Layer and Domain Classes Getting from Classes to a Database Working with Configuration Creating or Pointing to a Database What Code First Does Not Support Learning from This Book 2. Your First Look at Code First Introducing EF to nullable foreign key the Domain Classes Putting the Pieces Together in an Example Overriding Convention with Configurations Understanding How Model Changes Impact Database Initialization Configuring Code First with the Fluent API Summary 3. Using Conventions and Configurations for Property Attributes Working with Property Attributes in Code First Mapping Keys Configuring Database-Generated Properties Configuring TimeStamp/RowVersion Fields for Optimistic Concurrency Configuring Non-Timestamp Fields for Concurrency Mapping to Non-Unicode Database Types Affecting the Precision and Scale of Decimals Working with Complex Types in Code First Configuring Properties of Complex Types Summary 4. Using Convention and Configuration for Relationships Working with Multiplicity Working with Foreign Keys Working with Inverse Navigation Properties Working with Cascade Delete Exploring Many-to-Many Relationships Working with Relationships that Have Unidirectional Navigation Working with One-to-One Relationships Summary 5. Using Conventions and Configurations for Database Mappings Mapping Class Name to Database Table and Schema Name Mapping Property Names to Database Columns Allowing Multiple Entities to Map to a Single Table: aka Table Splitting
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