ASP.Net MVC 3 EF“上表将外键约束可能会引起循环或多个级联路径”(ASP.Net MV

我创建一个ASP.Net MVC 3应用程序，我试图用迁移来更新我的数据库，当运行到一个外键约束问题。我使用的代码优先，而我得到的错误是：

表“CategoryItemValues”引入外来KEY约束“FK_CategoryItemValues_CategoryProperties_CategoryPropertyId”可能会导致循环或多个级联路径。指定ON DELETE NO ACTION或ON UPDATE NO ACTION，或修改其他外键约束。无法创建约束。请参阅以前的错误。

这里是我的类：

public class Category
{
    public int Id { get; set; }
    [Display(Name = "Category Name")]
    public string CategoryName { get; set; }
    [Display(Name = "Display Name")]
    public string DisplayName { get; set; }
    [Display(Name = "Display Order")]
    public int DisplayOrder { get; set; }
    public bool IsTab { get; set; }
    public bool Active { get; set; }

    public virtual List<CategoryProperty> Properties { get; set; }
}

public class CategoryProperty
{
    public int Id { get; set; }
    public int CategoryId { get; set; }
    [Display(Name="Property Name")]
    public string PropertyName { get; set; }
    [Display(Name = "Display Order")]
    public int DisplayOrder { get; set; }

    public virtual Category Category { get; set; }
}

public class CategoryItem
{
    public int Id { get; set; }
    public int CategoryId { get; set; }

    public virtual Category Category { get; set; }
    public virtual List<CategoryItemValue> Values { get; set; }
}

public class CategoryItemValue
{
    public int Id { get; set; }
    public int CategoryItemId { get; set; }
    public int CategoryPropertyId { get; set; }
    public string Value { get; set; }

    public virtual CategoryItem Item { get; set; }
    public virtual CategoryProperty Property { get; set; }
}

protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
    // I know that the solution needs to go here!
}

好像我需要在删除CategoryItemValues禁用级联，但我不知道该怎么做。我知道我需要做的是这样的：

modelBuilder.Entity <...>（）.HasRequired（...）.WithMany（...）.HasForeignKey（...）.WillCascadeOnDelete（假）;

但我不能把它完全正确。

这应该工作...

public class Category
{
    public int Id { get; set; }
    public string CategoryName { get; set; }
    public string DisplayName { get; set; }
    public int DisplayOrder { get; set; }
    public bool IsTab { get; set; }
    public bool Active { get; set; }
    public virtual List<CategoryProperty> Properties { get; set; }
    public virtual List<CategoryItem> Items { get; set; }
}
public class CategoryProperty
{
    public int Id { get; set; }
    public int CategoryId { get; set; }
    public string PropertyName { get; set; }
    public int DisplayOrder { get; set; }
    public virtual Category Category { get; set; }
    public virtual List<CategoryItemValue> Values { get; set; }
}
public class CategoryItem
{
    public int Id { get; set; }
    public int CategoryId { get; set; }
    public virtual Category Category { get; set; }
    public virtual List<CategoryItemValue> Values { get; set; }
}
public class CategoryItemValue
{
    public int Id { get; set; }
    public int CategoryItemId { get; set; }
    public int CategoryPropertyId { get; set; }
    public string Value { get; set; }
    public virtual CategoryItem Item { get; set; }
    public virtual CategoryProperty Property { get; set; }
}

......和“要点” ......

modelBuilder.Entity<CategoryProperty>()
    .HasKey(i => i.Id);

modelBuilder.Entity<CategoryProperty>()
    .HasRequired(i => i.Category)
    .WithMany(u => u.Properties)
    .HasForeignKey(i => i.CategoryId)
    .WillCascadeOnDelete(false);

modelBuilder.Entity<CategoryItem>()
    .HasKey(i => i.Id);

modelBuilder.Entity<CategoryItem>()
    .HasRequired(i => i.Category)
    .WithMany(u => u.Items)
    .HasForeignKey(i => i.CategoryId)
    .WillCascadeOnDelete(false);

modelBuilder.Entity<CategoryItemValue>()
    .HasKey(i => i.Id);

modelBuilder.Entity<CategoryItemValue>()
    .HasRequired(i => i.Item)
    .WithMany(u => u.Values)
    .HasForeignKey(i => i.CategoryItemId)
    .WillCascadeOnDelete(false);

modelBuilder.Entity<CategoryItemValue>()
    .HasRequired(i => i.Property)
    .WithMany(u => u.Values)
    .HasForeignKey(i => i.CategoryPropertyId)
    .WillCascadeOnDelete(false);