Elasticsearch多层嵌套查询如何仅返回匹配的嵌套路径数据

Elasticsearch的nested查询默认返回符合条件的完整文档_source，不会自动过滤未匹配的嵌套数组元素。要实现仅返回匹配的嵌套对象，需要在第二层嵌套查询中添加inner_hits配置，同时可以选择关闭原始_source的返回避免冗余。

调整后的查询语句 #

GET /drivers/_search
{
  "_source": false, 
  "query": {
    "nested": {
      "path": "driver",
      "query": {
        "nested": {
          "path": "driver.vehicle",
          "query": {
            "bool": {
              "must": [
                { "match": { "driver.vehicle.make": "Powell Motors" } },
                { "match": { "driver.vehicle.model": "Canyonero" } }
              ]
            }
          },
          "inner_hits": {} 
        }
      }
    }
  }
}

返回结果说明 #

调整后返回结果会新增inner_hits字段，里面仅包含匹配的vehicle对象，示例如下：

{
  "took" : 5,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 1,
      "relation" : "eq"
    },
    "max_score" : 3.7349272,
    "hits" : [
      {
        "_index" : "drivers",
        "_type" : "_doc",
        "_id" : "1",
        "_score" : 3.7349272,
        "inner_hits" : {
          "driver.vehicle" : {
            "hits" : {
              "total" : {
                "value" : 1,
                "relation" : "eq"
              },
              "max_score" : 3.7349272,
              "hits" : [
                {
                  "_nested" : {
                    "field" : "driver",
                    "offset" : 0,
                    "_nested" : {
                      "field" : "vehicle",
                      "offset" : 0
                    }
                  },
                  "_score" : 3.7349272,
                  "_source" : {
                    "make" : "Powell Motors",
                    "model" : "Canyonero"
                  }
                }
              ]
            }
          }
        }
      }
    ]
  }
}

补充说明 #

• 如果需要同时保留文档其他字段（比如driver.last_name），可以把_source设置为你需要返回的字段列表，例如"_source": ["driver.last_name"]
• inner_hits支持额外配置，比如分页、排序等，可根据业务需求调整参数。

内容的提问来源于stack exchange，提问作者Rajat Jain