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POForeign key constraint, EF with collection of childobjects
 

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    <p>I'm trying to update a model, but get the 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."</p> <p>From what I understand from <a href="https://stackoverflow.com/questions/5538974/the-relationship-could-not-be-changed-because-one-or-more-of-the-foreign-key-pro">The relationship could not be changed because one or more of the foreign-key properties is non-nullable</a> the problem might be with how Entity Framework handles my virtual ICollection</p> <p>However I'm not really sure how to implement the solution when using scaffolded repository pattern. Do I have to edit the Save()-method ParentObjectRepository-class?</p> <p>Actually I really think that there must be some way to make EF understand this. I can't see how the EF-team was thinking "Probably noone is using a collection of objects with a foreign key constraint, lets not support that".</p> <p><strong>Update</strong> Added code</p> <pre><code>[HttpPost] public ActionResult Edit(int id, FormCollection formCollection) { var eventRepository = new MagnetEventRepository(); var original = eventRepository.Find(id); UpdateModel(original); eventRepository.Save(); return RedirectToAction("Details", "Home", new { slug = original.Slug }); } public void Save() { context.SaveChanges(); } </code></pre> <p>More code:</p> <pre><code>public class MagnetEvent { public virtual int Id { get; set; } [Required] public virtual string Name { get; set; } [Required] [DisplayFormat(DataFormatString = "{0:yyyy-MM-dd HH:mm}")] [DataType(DataType.DateTime)] public virtual DateTime? StartDate { get; set; } public virtual string Description { get; set; } [StringLength(100)] public virtual string Slug { get; set; } public virtual int MaximumCapacity { get; set; } [DataType(DataType.Currency)] public virtual int TicketPrice { get; set; } public virtual int LocationId { get; set; } public virtual Location Location { get; set; } public virtual Collection&lt;Ticket&gt; Tickets { get; set; } public virtual Collection&lt;AttendeeInformationField&gt; CaptureAttendeeInformationFields { get; set; } public virtual int CustomerId { get; set; } [Required] public virtual CUSTOMER Customer { get; set; } } </code></pre> <p>The Save()-method is from MagnetEventRepository, which is scaffolded from the above class.</p> <p><strong>Another update</strong> I successfully removed the error by changing MagnetEventId in AttendeeInformationField to nullable int. When examining the database I can see exactly what's wrong.</p> <p>Let's say I have a single AttendeeInformationField with the value "E-mail". When I edit my MagnetEvent, the AttendeeInformationField updates the MagnetEventId to null and then adds a new post with the correct MagnetEventId and Value.</p> <p>I'd very much prefer if the posts in AttendeeInformationField were updated instead.</p>
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    1. USCommunity
    1. USStefan Bergfeldt
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    1. COCan you post your query and update code?
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      1. USLuke McGregor
    2. COSure, I updated original post.
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      1. USStefan Bergfeldt
 

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