我的应用程序有一个要求，即应该能够过滤/搜索 PairsPhụ thuộc vào Number相关的Liên hệ .

一个 Đôi总是有一个对 Liên hệ 的引用存储，但联系人的号码不会也不会存储在引用中。所以我尝试为此创建一个自定义索引，因为 ĐôiVà Liên hệ存储在不同的集合中。

索引的简化示例如下所示。

public class Pairs_Search : AbstractMultiMapIndexCreationTask
{
    public class Result
    {
        public string Id { get; set; }
        public string Workspace { get; set; }
        public ContactResult Contact { get; set; }
        public bool HasContactDetails { get; set; }
    }

    public class ContactResult
    {
        public string Id { get; set; }
        public string Name { get; set; }
        public int Number { get; set; }
    }

    public Pairs_Search()
    {
        AddMap(pairs => pairs
            .Select(p => new
                {
                    p.Id,
                    p.Workspace,
                    Contact = new
                    {
                        p.Contact.Id,
                        p.Contact.Name,
                        Number = 0
                    },
                    // Mark this items as WITHOUT contact details.
                    HasContactDetails = false,
                }
            )
        );

        AddMap(contacts => contacts
            .Select(c => new
                {
                    Id = (string) null,
                    Workspace = (string) null,
                    Contact = new
                    {
                        c.Id,
                        Name = c.DisplayName,
                        c.Number
                    },
                    // Mark this items as WITH contact details.
                    HasContactDetails = true,
                }
            )
        );

        Reduce = results => results
            // First group by the contact ID. This will
            // create a group with 2 or more items. One with the contact
            // details, and one or more with pair details.
            // They are all marked by a boolean flag 'HasContactDetails'.
            .GroupBy(x => x.Contact.Id)
            // We are going to enrich each item in the current group, that is
            // marked as 'HasContactDetails = false', with the contact number.
            // We need that so that we can filter on it later.
            .Select(group =>
                group
                    .Select(i => new
                        {
                            i.Id,
                            i.Workspace,
                            Contact = new
                            {
                                i.Contact.Id,
                                i.Contact.Name,
                                // Does the current item have the contact details?
                                Number = i.HasContactDetails
                                    // Yes, in this case we use the previously set contact number.
                                    ? i.Contact.Number
                                    // No, find the item with the contact details and grab the number.
                                    : group.Single(x => x.HasContactDetails).Contact.Number
                            },
                            // Pass on the flag that indicates wheter or not
                            // this item has the contact details. We are going
                            // to need it later.
                            i.HasContactDetails
                        }
                    )
                    // We don't need the items with the contact details
                    // anymore, so filter them out.
                    .Where(x => !x.HasContactDetails)
            )
            // Flatten all the small lists to one big list.
            .SelectMany(x => x);

        // Mark the following fields of the result as searchable.
        Index(x => x.Contact.Number, FieldIndexing.Search);
    }
}

我已经设置了一个完整的示例来重现我遇到的问题。您可以找到示例 đây .

创建索引工作正常。查询索引也能正常工作，因为它正确匹配了对和联系人，并用联系人的数量丰富了索引结果。但是当我尝试使用 .Where() 时或 .Search()在嵌套 Number属性，它无法从索引中正确过滤结果数据集。

没有任何过滤的索引可以在下面的代码示例中看到(在完整示例中也可用)。

private static async Task ThisOneWorks()
{
    using (var session = Store.OpenAsyncSession())
    {
        var results = await session
            .Query()
            .ToListAsync(); 

        LogResults("ThisOneWorks()", results);              
    }

    // Output:
    // ThisOneWorks(): Pair 'Harry Potter' with number '70'
    // ThisOneWorks(): Pair 'Harry Potter' with number '70'
    // ThisOneWorks(): Pair 'Hermione Granger' with number '71'
    // ThisOneWorks(): Pair 'Albus Dumbledore' with number '72'
}

过滤非嵌套值也有效(在完整示例中也可用)。如您所见，它过滤掉了具有不同工作区的那个。

private static async Task ThisOneWithWorkspaceFilterWorks()
{
    using (var session = Store.OpenAsyncSession())
    {
        var results = await session                 
            .Query()
            .Where(x => x.Workspace == "hogwarts")
            .ToListAsync(); 

        LogResults("ThisOneWithWorkspaceFilterWorks()", results);               
    }

    // Output:
    // ThisOneWithWorkspaceFilterWorks(): Pair 'Harry Potter' with number '70'
    // ThisOneWithWorkspaceFilterWorks(): Pair 'Harry Potter' with number '70'
    // ThisOneWithWorkspaceFilterWorks(): Pair 'Hermione Granger' with number '71'
}

当我尝试在 Workspace 上过滤/搜索时和 Number属性 我希望有两个结果与接触哈利波特有关。但相反，我只是得到一个空的数据集。

private static async Task ThisOneWithWorkspaceAndNumberFilterDoesntWork()
{
    using (var session = Store.OpenAsyncSession())
    {
        var results = await session                 
            .Query()
            .Where(x => x.Workspace == "hogwarts")
            .Where(x => x.Contact.Number == 70)
            .ToListAsync(); 

        LogResults("ThisOneWithWorkspaceAndNumberFilterDoesntWork()", results);             
    }

    // Output:
    // ThisOneWithWorkspaceAndNumberFilterDoesntWork(): EMPTY RESULTS!
}

谁能告诉我我在这里做错了什么？任何帮助将不胜感激!

1 Câu trả lời

解决方法是将 ContactResult 存储在不同的集合中，
这就是所谓的 相关文档在这种情况下，
当你创建索引时，你会'索引相关文档 '

từ 中的演示示例中学习:
https://demo.ravendb.net/demos/csharp/related-documents/index-related-documents
该示例适用于基本 map 索引，但原理与 Multi-Map 相同。

xóa bỏ public class ContactResult从索引类
并使用以下内容定义索引:

         select new Result
        {
            ....
            Number = LoadDocument(Pair.Contact).Number
            .... 
        }

关于indexing - RavenDB:如何从 MultiMapIndex 正确查询/过滤嵌套值？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/62285344/