Java RavenDB查询返回null

我在Ravendb3.5.35183上。我有一种类型：

import com.mysema.query.annotations.QueryEntity;

@QueryEntity
public class CountryLayerCount
{
    public String countryName;
    public int layerCount;
}

以及以下查询：

private int getCountryLayerCount(String countryName, IDocumentSession currentSession)
{           
    QCountryLayerCount countryLayerCountSurrogate = QCountryLayerCount.countryLayerCount;
    IRavenQueryable<CountryLayerCount> levelDepthQuery = currentSession.query(CountryLayerCount.class, "CountryLayerCount/ByName").where(countryLayerCountSurrogate.countryName.eq(countryName));
    CountryLayerCount countryLayerCount = new CountryLayerCount();
    try (CloseableIterator<StreamResult<CountryLayerCount>> results = currentSession.advanced().stream(levelDepthQuery))
    {
        while(results.hasNext())
        {
            StreamResult<CountryLayerCount> srclc = results.next();
            System.out.println(srclc.getKey());
            CountryLayerCount clc = srclc.getDocument();
            countryLayerCount = clc;
            break;
        }
    }
    catch(Exception e)
    {
    }
    return countryLayerCount.layerCount;
}

当插入浏览器时，它正确地为我提供：

{"Results":[{"countryName":"Germany","layerCount":5,"@metadata":{"Raven-Entity-Name":"CountryLayerCounts","Raven-Clr-Type":"DbUtilityFunctions.CountryLayerCount, DbUtilityFunctions","@id":"CountryLayerCounts/212","Temp-Index-Score":0.0,"Last-Modified":"2018-02-03T09:41:36.3165473Z","Raven-Last-Modified":"2018-02-03T09:41:36.3165473","@etag":"01000000-0000-008B-0000-0000000000D7","SerializedSizeOnDisk":164}}
]}

索引定义：

from country in docs.CountryLayerCounts
select new {
    CountryName = country.countryName
} 

顺便说一句，不必为对象的所有字段编制索引就可以完整地检索它，对吗？换句话说，我只需要索引字段来查找对象，而不是所有我想要检索的字段；至少这是我的理解

---

谢谢

问题与不正确的套管有关

例如：

try (IDocumentSession sesion = store.openSession()) {
    CountryLayerCount c1 = new CountryLayerCount();
    c1.layerCount = 5;
    c1.countryName = "Germany";

    sesion.store(c1);
    sesion.saveChanges();
}

保存为：

{
    "LayerCount": 5,
    "CountryName": "Germany"
}

请注意，我们在json中使用大写字母作为属性名称（这仅适用于3.X版本）

因此，为了使其正常工作，请更新json属性名称并编辑索引：

from country in docs.CountryLayerCounts
select new {
    CountryName = country.CountryName
} 

顺便说一句，如果您有每个国家/地区的汇总，那么您只需使用以下工具进行查询：

QCountryLayerCount countryLayerCountSurrogate = 
QCountryLayerCount.countryLayerCount;
    CountryLayerCount levelDepthQuery = currentSession
            .query(CountryLayerCount.class, "CountryLayerCount/ByName")
            .where(countryLayerCountSurrogate.countryName.eq(countryName))
            .single();

---

CountryLayerCount/ByName

看起来像什么？@Ayende:更新了问题谢谢你提供了一个详细、简洁且非常有用的答案。我的责任可能是没有正确阅读文档和依赖假设。。。

QCountryLayerCount countryLayerCountSurrogate = 
QCountryLayerCount.countryLayerCount;
    CountryLayerCount levelDepthQuery = currentSession
            .query(CountryLayerCount.class, "CountryLayerCount/ByName")
            .where(countryLayerCountSurrogate.countryName.eq(countryName))
            .single();