在Entity Framework Core中向同一表添加具有多个一对一关系的实体时，堆栈溢出 [英] Stack overflow when adding an entity with multiple one-to-one relationship with the same table in Entity Framework Core

问题描述

在Entity Framework Core中向同一表添加具有多个一对一关系的实体时，我遇到问题。基于此问题，我有以下事情：

I have an issue when adding entities with multiple one-to-one relationship with the same table in Entity Framework Core. Based on this question I have the following things:

public class Article
{
    public int Id { get; set; }
    public int? PreviousId { get; set; }
    public Article Previous { get; set; }
    public int? NextId { get; set; }
    public Article Next { get; set; }
}

在 OnModelCreating DbContext >

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    base.OnModelCreating(modelBuilder);

    modelBuilder.HasDefaultSchema("ab");
    modelBuilder.ApplyConfiguration(new ArticleEntityTypeConfiguration());
}

public class ArticleEntityTypeConfiguration : IEntityTypeConfiguration<Article>
{
    public void Configure(EntityTypeBuilder<Article> builder)
    {
        builder.ToTable("Articles");

        builder.HasKey(table => table.Id);
        builder.Property(table => table.Id).ValueGeneratedOnAdd();

        builder.HasOne(table => table.Previous).WithOne().HasForeignKey<Article>(table => table.PreviousId);
        builder.HasOne(table => table.Next).WithOne().HasForeignKey<Article>(table => table.NextId);
    }
}

当添加新文章时，我得到了堆栈溢出错误，应用崩溃。我添加了具有以下代码的文章：

And when adding a new article I get a stack overflow error and the app crashes. I add an article with the following code:

public Task AddNewArticleAsync(Article article)
{
    var newArticle = new Article();

    article.Next = newArticle;
    newArticle.Previous = article;

    await _dbContext.Programs.AddAsync(article);
}

您知道如何避免该错误吗？谢谢！

Do you know how can I avoid that error? Thanks!

推荐答案

所以我继续对此进行调查并发现此答案有助于我解决此问题。诀窍是将 DbContext 的 OnModelCreating 更改为：

So I continue investigating about this and found this answer which helped me to fix the issue. The trick was to change the OnModelCreating of the DbContext to:

public void Configure(EntityTypeBuilder<Article> builder)
{
    builder.ToTable("Articles");

    builder.HasKey(table => table.Id);
    builder.Property(table => table.Id).ValueGeneratedOnAdd();

    builder
        .HasOne(table => table.Previous)
        .WithOne() // <-- one of this must be empty
        .HasForeignKey<Article>(table => table.PreviousId)
        .OnDelete(DeleteBehavior.Restrict);

    builder
        .HasOne(table => table.Next)
        .WithOne(table => table.Previous)
        .HasForeignKey<Article>(table => table.NextId);
}

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