Elasticsearch multiplequery/Python搜索

Question

我是Python和Elasticsearch的新手，我在Elasticsearch中创建了一个包含一些数据的索引，我想使用Python根据从用户收到的一些过滤器（关键字、类别）对它们执行查询

from elasticsearch import Elasticsearch
import json,requests

es = Elasticsearch(HOST="http://localhost", PORT=9200)
es = Elasticsearch()

def QueryMaker (keyword,category):
   response = es.search(index="main-news-test-data",body={"from":0,"size":10000,"query":{
       "bool": {
      "should": [
        {
          "multi_match" : {
            "query":      keyword,
            "fields":     [ "content", "title","lead" ]
          }
        },
        {
          "multi_match" : {
            "query":      category,
            "fields":     [ "category" ]
          }
        }
      ]
    }
   }})
   return(response)

def Mapper (category):
 fhandle = open('categories.txt','r', encoding="utf8")
 for line in fhandle:
     line = line.rstrip()
     items = line.split(';')
     if f'"{category}"' in items:
         category = items[0]
         return(category)

if __name__ == '__main__': 
    keyword = input('Enter Keyword: ')
    print(type(keyword))
    category = input('Enter Category: ')
    print(type(category))
    #startDate = input('Enter StartDate: ')
    #endDate = input('Enter EndDate: ')
    
    mapCategory = Mapper(category)
    if mapCategory is not None:
      mapCategory = mapCategory.replace("%","")
      data = QueryMaker(keyword,mapCategory)
      print(data)
    else:
      data = QueryMaker(keyword,mapCategory)
      print(data)

问题是，这个程序只在2个字段已满时返回匹配的数据，但我希望它在1个类似字段的类别为空时也返回数据。当关键字为空时，它与“”类似，且不返回任何内容；当类别为空时，我收到此错误：

elasticsearch.exceptions.RequestError: RequestError(400, 'x_content_parse_exception', '[multi_match] unknown token [VALUE_NULL] after [query]')   

我做错了什么？如何修复搜索过滤器

Answer 1

添加带有索引数据、搜索查询和搜索结果的工作示例

根据您上面提到的注释，如果content字段不包含keyword，并且category字段包含category，则将对category字段执行搜索查询。这可以通过使用^{}来实现

索引数据：

{
    "content": "keyword a",
    "title": "b",
    "lead": "c",
    "category": "d"
}
{
    "content": "a",
    "title": "b",
    "lead": "c",
    "category": "category"
}
{
    "content": "keyword a",
    "title": "b",
    "lead": "c",
    "category": "category"
}

搜索查询：

{
  "query": {
    "bool": {
      "should": [
        {
          "multi_match": {
            "query": "keyword",
            "fields": [
              "content",
              "title",
              "lead"
            ]
          }
        },
        {
          "multi_match": {
            "query": "category",
            "fields": [
              "category"
            ]
          }
        }
      ],
      "minimum_should_match":1
    }
  }
}

搜索结果：

"hits": [
      {
        "_index": "stof_64081587",
        "_type": "_doc",
        "_id": "3",
        "_score": 0.9666445,
        "_source": {
          "content": "keyword a",
          "title": "b",
          "lead": "c",
          "category": "category"
        }
      },
      {
        "_index": "stof_64081587",
        "_type": "_doc",
        "_id": "2",
        "_score": 0.60996956,
        "_source": {
          "content": "keyword a",
          "title": "b",
          "lead": "c",
          "category": "d"
        }
      },
      {
        "_index": "stof_64081587",
        "_type": "_doc",
        "_id": "1",
        "_score": 0.35667494,
        "_source": {
          "content": "a",
          "title": "b",
          "lead": "c",
          "category": "category"
        }
      }
    ]