ElasticSearch:如何在字符串字段为空或空的情况下编写查询？

Question

我想查看有的文件media_url == '' || media_url == null.我有一个问题:

{
    "engagements": [
        "blah"
    ],
    "query": {
        "from": 0,
        "size": 2,
        "sort": [
            {
                "bookmarked": {
                    "order": "desc"
                }
            },
            {
                "created_at": {
                    "order": "desc"
                }
            }
        ],
        "facets": {},
        "query": {
            "filtered": {
                "query": {
                    "match_all": {}
                },
                "filter": {
                    "bool": {
                        "must": [
                            {
                                "term": {
                                    "car_id": "78778"
                                }
                            },
                            {
                                "range": {
                                    "created_at": {
                                        "gte": "2015-04-12T04:00:00.000Z",
                                        "lte": "2015-05-13T03:59:59.999Z"
                                    }
                                }
                            },
                            {
                                "term": {
                                    "media_url": ""
                                }
                            }
                        ],
                        "should": [
                            {
                                "term": {
                                    "bookmarked": false
                                }
                            }
                        ]
                    }
                }
            }
        },
        "aggregations": {
            "word_frequencies": {
                "terms": {
                    "field": "text",
                    "size": 150
                }
            }
        },
        "highlight": {
            "fields": {
                "text": {
                    "fragment_size": 1500
                }
            }
        }
    },
    "api": "_search"
}

但是,如果我执行上面所做的操作,则不会返回设置为null的记录.如何返回带有''或null作为media_url值的记录？

Answer 1

也许您可以尝试使用“或”过滤器。 http://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-or-filter.html

{
  "or": [
    {
      "term": {
        "media_url": ""
      }
    },
    {
      "term": {
        "media_url": null
      }
    }
  ]
}

编辑：这是完整的查询（未经测试，因为我没有示例文档/索引模板）

{
    "engagements": [
        "blah"
    ],
    "query": {
      "from": 0,
      "size": 2,
      "sort": [
         {
            "bookmarked": {
               "order": "desc"
            }
         },
         {
            "created_at": {
               "order": "desc"
            }
         }
      ],
      "facets": {},
      "query": {
         "filtered": {
            "query": {
               "match_all": {}
            },
            "filter": {
               "bool": {
                  "must": [
                     {
                        "term": {
                           "car_id": "78778"
                        }
                     },
                     {
                        "range": {
                           "created_at": {
                              "gte": "2015-04-12T04:00:00.000Z",
                              "lte": "2015-05-13T03:59:59.999Z"
                           }
                        }
                     },
                     {
                        "or": [
                           {
                              "term": {
                                 "media_url": ""
                              }
                           },
                           {
                              "term": {
                                 "media_url": null
                              }
                           }
                        ]
                     }
                  ],
                  "should": [
                     {
                        "term": {
                           "bookmarked": false
                        }
                     }
                  ]
               }
            }
         }
      },
      "aggregations": {
         "word_frequencies": {
            "terms": {
               "field": "text",
               "size": 150
            }
         }
      },
      "highlight": {
         "fields": {
            "text": {
               "fragment_size": 1500
            }
         }
      }
   },
   "api": "_search"
}