c# - EF代码先FLUENT : many to many with additional field in jointable

Question

我正在构建一个 wiki，其中包含由子文章组成的文章。一篇文章可以包含多个子文章，一个子文章可以附加到多个文章。在 jointable 中有一个 sortorder，它定义了特定文章的子文章的显示。父文章仅包含标题(和元数据)，没有文本，所有文本都通过子文章完成。

虽然可连接中的排序顺序是我在 atm 卡住的地方，但我无法通过查询访问它。希望有人能指出我正确的方向。

旁注:我在整个 MVC/EF 世界中都是新手，即使是 c#/vb 和 .NET 也是我几个月以来才在业余时间从事的工作。

我有这些类(class):

文章:

public class Article : BaseEntity
{

    private ICollection<Category> _categories;
    private ICollection<ArticleSubarticle> _subarticles;

    public string Title { get; set; }
    public int AuthorId { get; set; }
    public DateTime CreationDate { get; set; }
    public DateTime ?PublishDate { get; set; }
    public DateTime ?ChangeDate { get; set; }
    public bool Published { get; set; }

    public virtual ICollection<Category> Categories
    {
        get { return _categories ?? (_categories = new List<Category>()); }
        protected set { _categories = value; }
    }

    public virtual ICollection<ArticleSubarticle> Subarticles
    {
        get { return _subarticles ?? (_subarticles = new List<ArticleSubarticle>()); }
        protected set { _subarticles = value; }
    }

}

副文章

public class Subarticle : Article
    {

        private ICollection<Attachment> _attachments;

        public string ArticleText { get; set; }
        public int OriginalArticle { get; set; }
        public bool Active { get; set; }

        public virtual ICollection<Attachment> Attachments
        {
            get { return _attachments ?? (_attachments = new List<Attachment>()); }
            protected set { _attachments = value; }
        }

    }

可联合:

public class ArticleSubarticle : BaseEntity
    {

        public int ParentId { get; set; }
        public int ChildId { get; set; }

        public int SortOrder { get; set; }

        public virtual Article Parent { get; set; }
        public virtual Subarticle Child { get; set; }

    }

它们的映射如下:

文章

public ArticleMap () {

            ToTable("Wiki_Article");

            HasKey(a => a.Id);
            Property(a => a.Title).HasColumnType("VARCHAR").HasMaxLength(250);
            Property(a => a.AuthorId);
            Property(a => a.PublishDate).IsOptional();
            Property(a => a.ChangeDate).IsOptional();

            HasMany(a => a.Categories)
                .WithMany()
                .Map(a => a.ToTable("Wiki_Article_Category_Mapping"));



        }

副文章

public SubarticleMap()
        {

            ToTable("Wiki_Subarticle");
            HasKey(sa => sa.Id);

            Property(a => a.ArticleText)
                .IsOptional()
                .HasColumnType("TEXT");

            Property(a => a.OriginalArticle)
                .IsOptional();

            HasMany(a => a.Attachments)
                .WithMany()
                .Map(a => a.ToTable("Wiki_Subarticle_Attachment_Mapping"));

        }

可联合

public ArticleSubarticleMap()
        {

            ToTable("Wiki_Article_Subarticle_Mapping");

            HasKey(asa => new { asa.ParentId, asa.ChildId });

            HasRequired(asa => asa.Parent)
                .WithMany(asa => asa.Subarticles)
                .HasForeignKey(asa => asa.ParentId);

        }

这让我得到了预期的数据库。

现在我想要一篇文章及其子文章，它们按排序顺序排序。此查询为我提供了文章及其子文章，但我似乎无法弄清楚如何在 Wiki_Article_Subarticle_Mapping 表中找到此排序顺序。

public IList<Article> getArticleByIdWithSortedSubarticles(int ArticleId)
        {
            var query = _articleRepository.Table;
            query = query.Where(a => ArticleId == a.Id)
                         .Select(a => a);

            var subarticles = query.ToList();

            return subarticles;

        }

有什么想法吗？

提前致谢!

Answer 1

您的查询目前没有加载子文章，所以我猜它们是延迟加载的。尝试像这样显式加载它们:

public IList<Article> getArticleByIdWithSortedSubarticles(int ArticleId)
{
    var query = _articleRepository.Table;
    query = query.Where(a => ArticleId == a.Id)
                 .Select(a => new { article = a, subs = a.SubArticles.OrderBy(s => s.SortOrder) });

    return query.AsEnumerable().Select(m => m.article).ToList();
}