c# - 无法确定相关操作的有效顺序？

Question

我有这个模型:

public class ContentType
{
    public int ContentTypeId{get;set;}
    public string Name{get;set;}
    public Lang Lang{get;set;}
    public bool IsPublished{get;set;}
    public int? ParentId { get; set; }
    public int UserId { get; set; }
    public virtual User User { get; set; }
    public virtual ContentType Parent { get; set; }
    public virtual List<ContentType> Children { get; set; }
}

它与自身具有一对多的关系。

在上下文中我有这个:

protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
    modelBuilder.Entity<ContentType>().HasMany(c => c.Children).WithOptional(c => c.Parent).HasForeignKey(c => c.ParentId);
    base.OnModelCreating(modelBuilder);
    modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();    
}

但是当我使用 ParentId=0 保存记录时，我看到了这个错误:

Unable to determine a valid ordering for dependent operations. Dependencies may exist due to foreign key constraints, model requirements, or store-generated values.

请注意，由于以下错误，数据库中的关系不存在:

'ContentType' table - Unable to create relationship 'FK_ContentType_ContentType'. The ALTER TABLE statement conflicted with the FOREIGN KEY SAME TABLE constraint "FK_ContentType_ContentType". The conflict occurred in database "CMS", table "dbo.ContentType", column 'ContentTypeId'.

但我不认为问题出在此处。我不知道。

这里有什么问题吗？

Answer 1

看来这两个错误都是由于表ContentType中的数据不正确导致的。

'ContentType' table - Unable to create relationship 'FK_ContentType_ContentType'. The ALTER TABLE statement conflicted with the FOREIGN KEY SAME TABLE constraint "FK_ContentType_ContentType". The conflict occurred in database "CMS", table "dbo.ContentType", column 'ContentTypeId'.

这指向 ParentId 字段中的错误值。验证此字段中的值在其他记录中是否确实是正确的 ContentTypeId。

Unable to determine a valid ordering for dependent operations. Dependencies may exist due to foreign key constraints, model requirements, or store-generated values.

此错误指向循环依赖。验证您的数据中没有循环。