We want to be able to return a single document with a maximum value for a particular field. A typical example would be,
我们希望能够返回具有特定字段的最大值的单个文档。一个典型的例子是，
max(date_time_field:*)
which returns the latest document in the index.
它返回索引中的最新文档。
Is there any support for something like this in Lucene.Net?
在Lucene.Net中是否有类似的支持？
1 个解决方案
#1
3
I'm not sure how you are querying your index, but you can certainly order by the field in question, and then simply take the top document:
我不确定你是如何查询索引的，但你当然可以通过相关字段进行排序，然后只需获取最顶层的文档：
var sortBy = new Sort(new SortField("date_time_field", SortField.DOUBLE, true));
var hits = ... IndexSearcher.Search(query, null, 1, sortBy));
...
var doc = searcher.IndexSearcher.Doc(hits.ScoreDocs[0]);
#1
3
I'm not sure how you are querying your index, but you can certainly order by the field in question, and then simply take the top document:
我不确定你是如何查询索引的，但你当然可以通过相关字段进行排序，然后只需获取最顶层的文档：
var sortBy = new Sort(new SortField("date_time_field", SortField.DOUBLE, true));
var hits = ... IndexSearcher.Search(query, null, 1, sortBy));
...
var doc = searcher.IndexSearcher.Doc(hits.ScoreDocs[0]);