elasticsearch查询多字段聚合

1，需求：

在分页查询的同时，返回所查询商品的类目和品牌的聚合信息

2，mapping：
    {
        "item" : {
            "properties" : {
                "item_name" : {
                    "type" : "string",
                                        "index" : "analyzed",
                                        "analyzer" : "ik_smart"
                },
               "brand_name" : {
                    "type" : "multi_field",
                    "fields" : {
                        "brand_name" : {"type" : "string", "index" : "analyzed", "analyzer" :"ik_smart"},
                        "brand_name_agg" : {"type" : "string", "index" : "not_analyzed"}
                    }
                },
                "c_name" : {
                    "type" : "multi_field",
                    "fields" : {
                        "c_name" : {"type" : "string", "index" : "analyzed","analyzer" :"ik_smart"},
                        "c_name_agg" : {"type" : "string", "index" : "not_analyzed"}
                    }
                }
            }
        }
    }

这里需要注意的是brand_name如果设置为ik分词，聚合结果也会进行分词，导致结果不准确

可对brand_name进行multi_field设置，query时使用brand_name,agg时使用brand_name_agg

 

3，查询时需要注意如果分别统计两个不相关的字段，可设置aggregations下多个结果集，若统计有父子关系的字段，

例如某年级下某班级的学生个数，可使用subAggregation功能

search:

 {"from" : 0,
  "size" : 20,
  "query" : {
    "bool" : {
      "must" : {
        "fuzzy" : {
          "item_name" : {
            "value" : "西门子"
          }
        }
      }
    }
  },
  "explain" : true,
  "aggregations" : {
    "brand_name.brand_name_agg" : {
      "terms" : {
        "field" : "brand_name.brand_name_agg",
        "size" : 9999,
        "order" : {
          "_count" : "asc"
        }
      }
    },
    "c_name.c_name_agg" : {
      "terms" : {
        "field" : "c_name.c_name_agg",
        "size" : 9999,
        "order" : {
          "_count" : "asc"
        }
      }
    }
  }
}

 

4，相关java实现方式：

1)查询条件构建：

 

SearchRequestBuilder builder = client.prepareSearch(index).setTypes(type);

BoolQueryBuilder boolQueryBuilder = QueryBuilders.boolQuery();
TermsBuilder termsBuilder = AggregationBuilders.terms(aggregation.getField());
termsBuilder.field(aggregation.getField());
if(SortConstant.SortASC.equals(aggregation.getOrder())){
    termsBuilder.order(Terms.Order.aggregation("_count", true));
}else{
    termsBuilder.order(Terms.Order.aggregation("_count", false));
}
termsBuilder.size(aggregation.getSize());
builder.addAggregation(termsBuilder);

2）查询结果返回：

Map> aggrMap = new HashMap>(); List aggregationList = searchCondition.getAggregationList(); if(aggregationList!=null && aggregationList.size() > 0){ for(Aggregation aggregation : aggregationList){ List