RavenDB 数组搜索 returns 个随机结果

Question

我正在尝试使用 RavenDB 4 中的 Search 方法在字典之上执行搜索。奇怪的是，如果搜索词是 in 或 it 我得到随机结果。我绝对确定 none 的记录包含这些词。在 studio 上执行等效的 lucene 查询时也会发生这种情况。当我输入有效的搜索词（如员工姓名、编号等）时，它会按预期工作。

我已经根据真实场景创建了这个简单的场景。

这是索引：

public class Search : AbstractIndexCreationTask<Employee, Page>
{
    public Search()
    {
        Map = employees => from employee in employees
                           select new
                           {
                               Id = employee.Id,
                               Details = employee.Details
                           };

        Reduce = results => from result in results
                            group result by new
                            {
                                result.Id,
                                result.Details
                            }
                            into g
                            select new
                            {
                                g.Key.Id,
                                g.Key.Details
                            };

        Index("Details", FieldIndexing.Search);
    }
}

员工class：

public class Employee 
{
    public string Id { get; set; }
    public Dictionary<string, object> Details { get; set; }
}

添加员工：

details = new Dictionary<string, object>();
details.Add("EmployeeNo", 25);
details.Add("FirstNames", "Yuri");
details.Add("Surname", "Cardoso");
details.Add("PositionCode", "XYZ");
details.Add("PositionTitle", "Developer");

employee = new Employee
{
    Details = details
};

session.Store(employee);
session.SaveChanges();

搜索方式：

var searchTerm = "in";

var result = session
    .Query<Page, Search>()
    .Search(i => i.Details, $"EmployeeNo:({searchTerm})")
    .Search(i => i.Details, $"FirstNames:({searchTerm})", options: SearchOptions.Or)
    .Search(i => i.Details, $"Surname:({searchTerm})", options: SearchOptions.Or)
    .Search(i => i.Details, $"PositionCode:({searchTerm})", options: SearchOptions.Or)
    .Search(i => i.Details, $"PositionTitle:({searchTerm})", options: SearchOptions.Or)
    .ToList();

Lucene 查询输出：

from index 'Search' where search(Details, "EmployeeNo:(it)") 
or search(Details, "FirstNames:(it)") 
or search(Details, "Surname:(it)") 
or search(Details, "PositionCode:(it)") 
or search(Details, "PositionTitle:(it)")

知道为什么在输入这些特定单词时会返回随机结果吗？

Answer 1

问题是停用词。某些术语非常常见，以至于它们对于使用全文搜索进行搜索毫无意义。是，它，他们，是，等等。它们被查询分析器删除。请参阅此处的讨论：https://ravendb.net/docs/article-page/4.2/Csharp/indexes/using-analyzers

您可以使用空白分析器代替标准分析器，因为前者不会消除停用词。

Answer 2

在获得 RavenDB group 人员的帮助后，我们设法找到了适合我的场景的解决方案。

员工：

public class Employee
{
    public string Id { get; set; }
    public string DepartmentId { get; set; }
    public Dictionary<string, object> Details { get; set; }
}

部门：

public class Department
{
    public string Id { get; set; }
    public string Name { get; set; }
}

页数：

public class Page
{
    public string Id { get; set; }
    public string Department { get; set; }
    public Dictionary<string, object> Details { get; set; }
}

索引（dynamic fields）：

public class Search : AbstractIndexCreationTask<Employee, Page>
{
    public Search()
    {
        Map = employees => from employee in employees
                           let dept = LoadDocument<Department>(employee.DepartmentId)
                           select new
                           {
                               employee.Id,
                               Department = dept.Name,
                               _ = employee.Details.Select(x => CreateField(x.Key, x.Value))
                           };

        Store(x => x.Department, FieldStorage.Yes);
        Index(Constants.Documents.Indexing.Fields.AllFields, FieldIndexing.Search);
    }
}

查询：

using (var session = DocumentStoreHolder.Store.OpenAsyncSession())
{
    var searchTearm = "*yu* *dev*";

    var result = await session
        .Advanced
        .AsyncDocumentQuery<Page, Search>()
        .Search("Department", searchTearm)
        .Search("EmployeeNo", searchTearm)
        .Search("FirstNames", searchTearm)
        .Search("Surname", searchTearm)  
        .Search("PositionCode", searchTearm)
        .Search("PositionTitle", searchTearm)
        .SelectFields<Page>()
        .ToListAsync();
}

这样看来一切正常，不再有随机结果。非常感谢 Ayende 和 Egor。

RavenDB 数组搜索 returns 个随机结果

RavenDB array search returns random results

asp.net

lucene

ravendb