elasticsearch - 对于没有数据的字段，对嵌套 bool 查询返回空结果

Question

我正在执行以下查询:
ns.ns字段已配置(成功设置了映射和设置)，但是该字段没有源数据。我得到从ElasticSearch返回的空结果。那正确吗？我的意思是，没有数据，此查询将返回空结果，对吗？仍在学习ES，感谢您的帮助。

Answer 1

The ns.ns field has configured (has both mapping and setting set up successfully) but there is no source data for this field. and I get empty result returned from ElasticSearch. is that right? without data this query would return an empty result, is that correct?

如前所述，ns字段被映射为nested类型，因此，当您点击搜索查询时，由于该索引已经存在，因此不会得到"index_not_found_exception"。
search API返回与请求中定义的查询匹配的搜索命中。
当您点击上面问题中提到的搜索查询时，将出现以下响应:

 {
    "took": 17,
    "timed_out": false,
    "_shards": {
        "total": 1,
        "successful": 1,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 0,
            "relation": "eq"
        },
        "max_score": null,
        "hits": []
    }
}

该响应提供有关search request的以下信息:

took – how long it took Elasticsearch to run the query, in milliseconds

timed_out – whether or not the search request timed out

_shards – how many shards were searched and a breakdown of how many shards succeeded, failed, or were skipped.

max_score – the score of the most relevant document found

hits.total.value - how many matching documents were found

上面的hits.hits返回一个空数组([])，hits.hits是找到的符合搜索条件的文档的数组。由于此处没有索引文档，因此在命中搜索查询时不会匹配任何文档。
请参阅此ES文档，以了解有关how scoring works in ES的更多信息

In the above response max_score value is NULL, the _score in Elasticsearch is a way of determining how relevant a match is to the query.