Reverse_nested 聚合+top hits：同时获取父级和嵌套数据

Question

你知道如何使用 reverse_nested 聚合来获取我的热门聚合中的父数据和嵌套数据吗？ “唯一”部分是现在的问题。 这是我的映射：

{
    "ticket": {
        "mappings": {
            "properties": {
                "name": {
                    "type": "keyword"
                }
            },
            "tasks": {
                "type": "nested",
                "properties": {
                    "string_task_name": {
                        "type": "keyword"
                    }
                }
            }
        }
    }
}

我的查询使用热门匹配和反向嵌套聚合。

{
    "aggs": {
        "object_tasks": {
            "nested": {
                "path": "object_tasks"
            },
            "aggs": {
                "filter_by_tasks_attribute": {
                    "filter": {
                        "bool": {
                            "must": [
                                {
                                    "wildcard": {
                                        "object_tasks.string_task_name.keyword": "*"
                                    }
                                }
                            ]
                        }
                    },
                    "aggs": {
                        "using_reverse_nested": {
                            "reverse_nested": {
                                "path": "object_tasks"
                            },
                            "aggs": {
                                "names": {
                                    "top_hits": {
                                        "_source": {
                                            "includes": [
                                                "object_tasks.string_task_name",
                                                "string_name"
                                            ]
                                        },
                                        "sort": [
                                            {
                                                "object_tasks.string_task_name.keyword": {
                                                    "order": "desc"
                                                }
                                            }
                                        ],
                                        "from": 0,
                                        "size": 10
                                    }
                                }
                            }
                        }
                    }
                }
            }
        }
    }
}

{
    "hits": {
        "total": {
            "value": 25,
            "relation": "eq"
        },
        "max_score": null,
        "hits": [
            {
                "_index": "random_index",
                "_type": "_doc",
                "_id": "5",
                "_score": null,
                "_source": {
                    "object_tasks": [  ================> I don't want all these tasks names, I just want the task name of the current nested object I am in.
                                            {
                            "string_task_name": "task1"
                        },
                        {
                            "string_task_name": "task2"
                        },
                        {
                            "string_task_name": "task3"
                        },
                        {
                            "string_task_name": "task4"
                        }
                    ],
                    "string_name": "Dummy Ticket 854"
                },
                "sort": [
                    "seek_a_sme"
                ]
            }
        ]
    }
}

如您所见，结果是给了我 4 个任务名称。我想要的是只返回 1 个任务名称。

我发现的唯一解决方法是复制任务内的工单数据。但如果我能避免它，那就太棒了。

Answer 1

我不想要所有这些任务名称，我只想要我所在的当前嵌套对象的任务名称。

“我所在的当前嵌套对象”的陈述意味着您在在 nested 上下文中，但是当您逃脱时，您不能在其中它通过reverse_nested...

我不确定我是否真正理解您在这里的目的，但您可以根据object_tasks.string_task_name.keyword 的条款进行聚合，然后此聚合的键将作为个人“当前嵌套对象”，您正在追求：

{
  "size": 0,
  "aggs": {
    "object_tasks": {
      "nested": {
        "path": "object_tasks"
      },
      "aggs": {
        "filter_by_tasks_attribute": {
          "filter": {
            "bool": {
              "must": [
                {
                  "wildcard": {
                    "object_tasks.string_task_name.keyword": "*"
                  }
                }
              ]
            }
          },
          "aggs": {
            "by_string_task_name": {
              "terms": {
                "field": "object_tasks.string_task_name.keyword",
                "order": {
                  "_key": "desc"
                }, 
                "size": 10
              },
              "aggs": {
                "using_reverse_nested": {
                  "reverse_nested": {},
                  "aggs": {
                    "names": {
                      "top_hits": {
                        "_source": {
                          "includes": [
                            "string_name"
                          ]
                        },
                        "from": 0,
                        "size": 10
                      }
                    }
                  }
                }
              }
            }
          }
        }
      }
    }
  }
}

屈服

"aggregations" : {
  "object_tasks" : {
    ...
    "filter_by_tasks_attribute" : {
      ...
      "by_string_task_name" : {
        ...
        "buckets" : [
          {
            "key" : "task4",                <--
            ...
            "using_reverse_nested" : {
              ...
              "names" : {
                "hits" : {
                  ...
                  "hits" : [
                    {
                      ...
                      "_source" : {
                        "string_name" : "Dummy Ticket 854"  <--
                      }
                    }
                  ]
                }
              }
            }
          },
          {
            "key" : "task3",                <--
            ...
          },
          {
            "key" : "task2",                <--
            ...
          },
          {
            "key" : "task1",                <--
            ...
            }
          }
        ]
      }
    }
  }
}

请注意，top_hits 聚合不再需要排序 - 对于任何当前聚合的 terms 存储桶，object_tasks.string_task_name.keyword 将始终相同。我所做的是 order this terms aggregation by _key，其工作方式与 top_hits 排序相同。顺便说一句——你的参数是missing the nested path。