分层数据的 ABP AppService

Question

我需要一个 AppService 来加载带有实体递归集合的树视图：

===Products===
Id
Description
Price
Products[] ====> Id
                 Description
                 Price
                 Products[]

           ====> Id
                 Description
                 Price
                 Products[] ====> Id
                                  Description
                                  Price
                                  Products[]

有现成的class可以推导吗？如果没有，您能否建议 class 派生什么或实现什么接口，以及如何进行？

PS: 可能有完整的 CRUD 操作，但最重要的是了解如何加载数据。

Answer 1

您可以使用Include方法来指定要包含在查询结果中的相关数据。

请参考Loading Related Data。

您可以参考下面的示例。

using Microsoft.EntityFrameworkCore;
using System.Linq;

namespace EFQuerying.RelatedData
{
    public class Sample
    {
        public static void Run()
        {
            #region SingleInclude
            using (var context = new BloggingContext())
            {
                var blogs = context.Blogs
                    .Include(blog => blog.Posts)
                    .ToList();
            }
            #endregion

            #region IgnoredInclude
            using (var context = new BloggingContext())
            {
                var blogs = context.Blogs
                    .Include(blog => blog.Posts)
                    .Select(blog => new
                    {
                        Id = blog.BlogId,
                        Url = blog.Url
                    })
                    .ToList();
            }
            #endregion

            #region MultipleIncludes
            using (var context = new BloggingContext())
            {
                var blogs = context.Blogs
                    .Include(blog => blog.Posts)
                    .Include(blog => blog.Owner)
                    .ToList();
            }
            #endregion

            #region SingleThenInclude
            using (var context = new BloggingContext())
            {
                var blogs = context.Blogs
                    .Include(blog => blog.Posts)
                        .ThenInclude(post => post.Author)
                    .ToList();
            }
            #endregion

            #region MultipleThenIncludes
            using (var context = new BloggingContext())
            {
                var blogs = context.Blogs
                    .Include(blog => blog.Posts)
                        .ThenInclude(post => post.Author)
                            .ThenInclude(author => author.Photo)
                    .ToList();
            }
            #endregion

            #region MultipleLeafIncludes
            using (var context = new BloggingContext())
            {
                var blogs = context.Blogs
                    .Include(blog => blog.Posts)
                        .ThenInclude(post => post.Author)
                    .Include(blog => blog.Posts)
                        .ThenInclude(post => post.Tags)
                    .ToList();
            }
            #endregion

            #region IncludeTree
            using (var context = new BloggingContext())
            {
                var blogs = context.Blogs
                    .Include(blog => blog.Posts)
                        .ThenInclude(post => post.Author)
                        .ThenInclude(author => author.Photo)
                    .Include(blog => blog.Owner)
                        .ThenInclude(owner => owner.Photo)
                    .ToList();
            }
            #endregion

            #region Eager
            using (var context = new BloggingContext())
            {
                var blog = context.Blogs
                    .Single(b => b.BlogId == 1);

                context.Entry(blog)
                    .Collection(b => b.Posts)
                    .Load();

                context.Entry(blog)
                    .Reference(b => b.Owner)
                    .Load();
            }
            #endregion

            #region NavQueryAggregate
            using (var context = new BloggingContext())
            {
                var blog = context.Blogs
                    .Single(b => b.BlogId == 1);

                var postCount = context.Entry(blog)
                    .Collection(b => b.Posts)
                    .Query()
                    .Count();
            }
            #endregion

            #region NavQueryFiltered
            using (var context = new BloggingContext())
            {
                var blog = context.Blogs
                    .Single(b => b.BlogId == 1);

                var goodPosts = context.Entry(blog)
                    .Collection(b => b.Posts)
                    .Query()
                    .Where(p => p.Rating > 3)
                    .ToList();
            }
            #endregion
        }
    }
}

Answer 2

_productRepository .GetAllIncluding(x=>x.Products) .Where(p => p.Id == 1); // 或者任何条件 .ToList()

这将为您提供 ID 为 1 的产品和子产品的列表。

分层数据的 ABP AppService

ABP AppService for hierarchical data

hierarchical-data

devextreme

aspnetboilerplate