白宫网站 wordpress,wordpress 翻译不起作用,wordpress主机空间选择,加工平台v型架0. 引言
某些业务场景下#xff0c;我们要对数组元素进行聚合查询#xff0c;就需要用到nested数据类型#xff0c;但部分场景是针对数组中指定的元素进行聚合#xff0c;于是就需要对数组元素进行限定#xff0c;今天来看看这种场景如何实现。
1. 数据准备
首先我们准…0. 引言
某些业务场景下我们要对数组元素进行聚合查询就需要用到nested数据类型但部分场景是针对数组中指定的元素进行聚合于是就需要对数组元素进行限定今天来看看这种场景如何实现。
1. 数据准备
首先我们准备一下模拟数据一个订单下有各个商品我们需要统计销售额前3的生鲜商品
mapping如下
PUT orders
{settings: {number_of_replicas: 0,number_of_shards: 1},mappings: {properties: {order_no: {type: keyword},create_user: {type: keyword},product_list:{type: nested,properties: {name: {type: keyword},number: {type: integer},type: {type: keyword}}}}}
}提供点模拟数据供大家演练
POST orders/_bulk
{index:{}}
{order_no:1,create_user:张三,product_list:[{name:苹果, number:2, type:生鲜},{name:水壶, number:2, type:百货},{name:香蕉, number:4, type:生鲜}]}
{index:{}}
{order_no:2,create_user:李四,product_list:[{name:榴莲, number:1, type:生鲜},{name:小米手机, number:2, type:百货},{name:鲫鱼, number:5, type:生鲜}]}
{index:{}}
{order_no:2,create_user:周吴,product_list:[{name:苹果, number:4, type:生鲜},{name:香梨, number:2, type:生鲜},{name:毛巾, number:4, type:百货}]}2. 实现
以下实现基于elasticsearch 7.13.0版本
1、我们来看直接查询的情况
GET orders/_search
{size: 0,aggs: {product_agg: {nested: {path: product_list},aggs: {name_agg: {terms: {field: product_list.name},aggs: {number_sum: {sum: {field: product_list.number}},sort: {bucket_sort: {sort: [{number_sum.value: {order: desc}}],size: 3}}}}}}}
}不做商品类型筛选的话可以看到我们通过nested聚合来实现统计通过bucket_sort来实现排序同时再用size参数限定下前3输出即可实现我们的需求。 nested agg官方文档https://www.elastic.co/guide/en/elasticsearch/reference/7.13/search-aggregations-bucket-nested-aggregation.html bucket sort官方文档https://www.elastic.co/guide/en/elasticsearch/reference/7.13/search-aggregations-pipeline-bucket-sort-aggregation.html 但是从输出结果很明显的看出这不是我们想要的结果我们需要对数组内的type属性做一下筛选只需要“生鲜”商品
而实现上es中提供了filter参数供我们来筛选聚合元素我们可以利用它来实现聚合条件的筛选如下在官方文档中的filter用法如下
filter agg 官方文档地址https://www.elastic.co/guide/en/elasticsearch/reference/7.13/search-aggregations-bucket-filter-aggregation.html
这里需要注意的是要把嵌套的聚合新写一个agg然后放到filter同级下也就是作为filter的子聚合即将filter聚合的结果作为下一次聚合的入参
GET orders/_search
{size: 0,aggs: {product_agg: {nested: {path: product_list},aggs: {type_filter: {filter: {term: {product_list.type: 生鲜}},aggs: {name_agg: {terms: {field: product_list.name},aggs: {number_sum: {sum: {field: product_list.number}},sort: {bucket_sort: {sort: [{number_sum.value: {order: desc}}],size: 3}}}}}}}}}
}执行出来的结果如下符合预期
另外再附加上java client的实现代码供大家参考这里使用了RestHighLevelClient作为客户端 Resource
private RestHighLevelClient restClient;public void test() throws IOException {String outAggName product_agg;String filterAggName type_filter;String termAggName name_agg;TermsAggregationBuilder termsAggregationBuilder AggregationBuilders.terms(termAggName).field(product_list.name);SearchSourceBuilder searchBuilder new SearchSourceBuilder();searchBuilder.aggregation(AggregationBuilders.nested(outAggName, product_list).subAggregation(AggregationBuilders.filter(filterAggName, new TermQueryBuilder(product_list.type, 生鲜)).subAggregation(termsAggregationBuilder.subAggregation(AggregationBuilders.sum(number_sum).field(product_list.number)).order(BucketOrder.aggregation(number_sum.value, false)))));searchBuilder.size(0);SearchRequest searchRequest new SearchRequest(orders);searchRequest.source(searchBuilder);SearchResponse response restClient.search(searchRequest, RequestOptions.DEFAULT);MapString, Aggregation resultMap response.getAggregations().getAsMap();ParsedNested aggResults (ParsedNested) resultMap.get(outAggName);ParsedFilter filterAgg aggResults.getAggregations().get(filterAggName);ParsedStringTerms termAgg filterAgg.getAggregations().get(termAggName);List? extends Terms.Bucket buckets termAgg.getBuckets();for (Terms.Bucket bucket : buckets) {// TODO 获取分组结果}}
