Question

我有2个实体和一个连接表绑定在一起。创建文章效果很好。更新商品实体会引发此异常：

SqlException：DELETE语句与REFERENCE约束“ FK_ArticleGroups_Articles_ArticleID”冲突。数据库“ myDB”的表“ dbo.ArticleGroups”的列“ ArticleID”中发生了冲突。该声明已终止。

下面是我的课程和设置

Article.cs

public class Article
{
    public int ArticleId { get; set; }
    public string Title { get; set; }
    public virtual ICollection<ArticleGroup> ArticleGroups { get; set; } = new List<ArticleGroup>();
}

Group.cs

public class Group
{
   public int GroupId { get; set; }
   public string GroupName { get; set; }
   public virtual ICollection<ArticleGroup> ArticleGroups { get; set; } = new List<ArticleGroup>();
public virtual ICollection<GroupUser> GroupUsers { get; set; } = new List<GroupUser>();
}

ArticleGroup.cs

public class ArticleGroup
{
   public int ArticleId { get; set; }
   public Article Article { get; set; }
   public int GroupId { get; set; }
   public Group Group { get; set; }
}

AppDbContext.cs

protected override void OnModelCreating(ModelBuilder modelBuilder)
{ 
    .....
    modelBuilder.Entity<ArticleGroup>()
            .HasKey(e => new { e.ArticleID, e.GroupId });

        modelBuilder.Entity<ArticleGroup>()
            .HasOne(e => e.Article)
            .WithMany(e => e.ArticleKbGroups)
            .HasForeignKey(e => e.ArticleID)
            .OnDelete(DeleteBehavior.Restrict);

        modelBuilder.Entity<ArticleGroup>()
            .HasOne(e => e.Group)
            .WithMany(e => e.ArticleGroups)
            .HasForeignKey(e => e.GroupId)
            .OnDelete(DeleteBehavior.Restrict);
}

public DbSet<Article> Articles { get; set; }
public DbSet<Group> Groups { get; set; }
public DbSet<ArticleGroup> ArticleGroups { get; set; }

ArticleRepository.cs

public bool UpdateArticle(Article article)
    {
        var articleGroups = _appDbContext.ArticleGroups.Where(a => a.ArticleID == article.ArticleID);
        _appDbContext.ArticleGroups.RemoveRange(articleGroups);
        _appDbContext.Articles.Update(article);
        return (_appDbContext.SaveChanges() >= 0);
    }

我已经看到了类似的问题，这些复杂的解决方案无法与如此琐碎的事物相提并论。我在EF的哪里设置不正确？我认为它的sql语句执行顺序不正确？

我认为游戏计划将从具有相同articleID的联接表中删除，并插入新值。

编辑

添加的关系

User.cs

public int UserId { get; set; }
    public string FullName { get; set; }
    public virtual ICollection<GroupUser> GroupUsers { get; set; } = new List<GroupUser>();

GroupUser.cs

public class GroupUser
{
    public int UserId { get; set; }
    public User User { get; set; }
    public int GroupId { get; set; }
    public Group Group { get; set; }
}

这也是这方面的另一种关系。这会导致错误吗？

我需要不要删除网上论坛，因为它们可能属于另一篇文章。

编辑2

protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<GroupUser>()
            .HasKey(e => new { e.UserId, e.GroupId }); 

        modelBuilder.Entity<GroupUser>()
            .HasOne(e => e.User)
            .WithMany(e => e.GroupUsers)
            .HasForeignKey(e => e.UserId)
            .OnDelete(DeleteBehavior.Restrict);

        modelBuilder.Entity<GroupUser>()
            .HasOne(e => e.Group)
            .WithMany(e => e.GroupUsers)
            .HasForeignKey(e => e.GroupId)
            .OnDelete(DeleteBehavior.Restrict);

        modelBuilder.Entity<ArticleGroup>()
            .HasKey(e => new { e.ArticleId, e.GroupId });

        modelBuilder.Entity<ArticleGroup>()
            .HasOne(e => e.Article)
            .WithMany(e => e.ArticleGroups)
            .HasForeignKey(e => e.ArticleId)
            .OnDelete(DeleteBehavior.Restrict);

        modelBuilder.Entity<ArticleGroup>()
            .HasOne(e => e.Group)
            .WithMany(e => e.ArticleGroups)
            .HasForeignKey(e => e.GroupId)
            .OnDelete(DeleteBehavior.Restrict);
}

更新具有多对多关系的实体时出现错误（JOIN TABLE）

0 个答案: