Question

我正在使用Linq到Sql并且具有多对多关系，因此使用关系表。

当我尝试插入关系/关联数据时，我收到错误。

我使用手动架构创建。

我的简化代码：

第一个表/类Booklet有这个关联：

    private EntitySet<BookletChapterRel> _bookletChapterRel = new EntitySet<BookletChapterRel>();

    [Association(Name = "ep_booklet_ep_book_chap_rel", OtherKey = "BookletID", ThisKey = "BookletID", Storage = "_bookletChapterRel")]
    public EntitySet<BookletChapterRel> BookletChapterRel
    {
        set { _bookletChapterRel.Assign(value); }
        get { return _bookletChapterRel; }
    }

BookletChapterRel有这两个关联：

    internal EntityRef<Booklet> _booklet;
    [Association(Name = "ep_booklet_ep_book_chap_rel", OtherKey = "BookletID", ThisKey = "BookletID", Storage = "_booklet", IsForeignKey = true, DeleteOnNull = true, DeleteRule = "CASCADE")]
    public Booklet Booklet
    {
        get { return _booklet.Entity; }
        set { _booklet.Entity = value; BookletID = value.BookletID; }
    }

    internal EntityRef<Chapter> _chapter;
    [Association(OtherKey = "ChapterID", ThisKey = "ChapterID", Storage = "_chapter")]
    public Chapter Chapter
    {
        get { return _chapter.Entity; }
        set { _chapter.Entity = value; ChapterID = value.ChapterID; }
    }

章节有这种关联：

    internal EntityRef<BookletChapterRel> _bookletChapterRel;
    [Association(OtherKey = "ChapterID", ThisKey = "ChapterID", Storage = "_bookletChapterRel")]
    public BookletChapterRel BookletChapterRel
    {
        get { return _bookletChapterRel.Entity; }
        internal set { _bookletChapterRel.Entity = value; ChapterID = value.ChapterID; }
    }

我尝试做一个简单的插入：

Booklet b = new Booklet();
b.NumberOfPages = 0;
b.Title = "Hello";
b.DateCreated = DateTime.Now;
b.DateModified = DateTime.Now;

bookletRepository.addBooklet(b); //Just calls booklettable.InsertOnSubmit()

var bookChapRel = new BookletChapterRel()
{
    ChapterID = 23,
    ViewOrder = 0
};

b.BookletChapterRel.Add(bookChapRel);

bookletRepository.SubmitBookletChanges();

但每次我得到例外：

The INSERT statement conflicted with the FOREIGN KEY constraint "FK_ep_book_chap_rel_ep_booklet". The conflict occurred in database "easypiecy_v2", table "dbo.ep_booklet", column 'BookletID'.

如果我使用EntityRef执行类似操作，则没有问题。

我做错了什么？我试图在自动模式生成的同一个数据库上做同样的事情，它工作正常。

谢谢，迈克尔。

Answer 1

ChapterID = 23

可能是问题所在。您的数据库是否允许您使用相同的章节创建BookletChapterRel？

BookletID是否在DB中自动增加？

Answer 2

好的，我在检查了汽车设计师代码后解决了这个问题：

而不是使用：

private EntitySet<BookletChapterRel> _bookletChapterRel = new EntitySet<BookletChapterRel>();

我必须像这样使用EntitySet重载：

private EntitySet<BookletChapterRel> _bookletChapterRel;

构造

public Booklet()
{
   _bookletChapterRel = new EntitySet<BookletChapterRel>(new Action<BookletChapterRel>(this.attach_ep_book_chap_rels), null);
}

向EntitySet添加实体抛出submitchanges上的异常（）

2 个答案: