聊聊Elasticsearch之Metric聚合
2022-12-28 10:12:08来源：今日头条
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此篇文章简单的记录一下elasticsearch的metric聚合操作。比如求 平均值、最大值、最小值、求和、总计、去重总计等。
2、准备数据2.1 准备mappingPUT /index_person{ "settings": { "number_of_shards": 1 }, "mappings": { "properties": { "id":{ "type": "long" }, "name": { "type": "keyword" }, "age": { "type": "integer" }, "class":{ "type": "text", "fielddata": true }, "province":{ "type": "keyword" } } }}2.2 准备数据PUT /index_person/_bulk{"index":{"_id":1}}{"id":1, "name":"张三","age":18,"class":"大一班","province":"湖北"}{"index":{"_id":2}}{"id":2, "name":"李四","age":19,"class":"大一班","province":"湖北"}{"index":{"_id":3}}{"id":3, "name":"王武","age":20,"class":"大二班","province":"北京"}{"index":{"_id":4}}{"id":4, "name":"赵六","age":21,"class":"大三班技术班","province":"北京"}{"index":{"_id":5}}{"id":5, "name":"钱七","age":22,"class":"大三班","province":"湖北"}3、metric聚合3.1 max 平均值3.1.1 dslPOST /index_person/_search{ "size": 0, "query": { "match_all": {} }, "aggs": { "agg_01": { "max": { "field": "age", "missing": 10 } } }}POST /index_person/_search{ "size": 0, "query": { "match_all": {} }, "aggs": { "agg_01": { "max": { "script": { "lang": "painless", "source": """ doc.age """ } } } }}POST /index_person/_search{ "size": 0, "query": { "match_all": {} }, "aggs": { "agg_01": { "max": { "field": "age", "script": { "lang": "painless", "source": """ _value * params.a """, "params": { "a": 2 } } } } }}3.1.2 java代码@Test@DisplayName("最大值聚合")public void test01() throws IOException { SearchRequest request = SearchRequest.of(searchRequest -> searchRequest.index("index_person") .size(0) .aggregations("agg_01", agg -> agg.max(max -> // 聚合的字段 max.field("age") // 如果聚合的文档缺失这个字段，则给10 .missing(10) ) ) ); System.out.println("request: " + request); SearchResponse response = client.search(request, String.class); System.out.println("response: " + response);}@Test@DisplayName("脚本聚合")public void test02() throws IOException { SearchRequest request = SearchRequest.of(searchRequest -> searchRequest.index("index_person") .size(0) .aggregations("agg_01", agg -> agg.max(max -> max.script(script -> script.inline(inline -> inline.lang(ScriptLanguage.Painless) // 脚本表达式 .source("doc.age") ) ) ) ) ); System.out.println("request: " + request); SearchResponse response = client.search(request, String.class); System.out.println("response: " + response);}@Test@DisplayName("值脚本聚合")public void test03() throws IOException { SearchRequest request = SearchRequest.of(searchRequest -> searchRequest.index("index_person") .size(0) .aggregations("agg_01", agg -> agg.max(max -> // 指定参与聚合的字段 max.field("age") .script(script -> script.inline(inline -> inline.lang(ScriptLanguage.Painless) // 脚本表达式 .source("_value * params.plus") // 参数 .params("plus", JsonData.of(2)) ) ) ) ) ); System.out.println("request: " + request); SearchResponse response = client.search(request, String.class); System.out.println("response: " + response);} 3.2 min最小值3.2.1 dslPOST /index_person/_search{ "size": 0, "query": { "match_all": {} }, "aggs": { "agg_01": { "min": { "field": "age", "missing": 10 } } }}3.2.2 javaPOST /index_person/_search{ "size": 0, "query": { "match_all": {} }, "aggs": { "agg_01": { "min": { "field": "age", "missing": 10 } } }}3.3 min最小值3.3.1 dslPOST /index_person/_search{ "size": 0, "query": { "match_all": {} }, "aggs": { "agg_01": { "avg": { "field": "age", "missing": 10 } } }}3.3.2 java@Test@DisplayName("平均值聚合")public void test01() throws IOException { SearchRequest request = SearchRequest.of(searchRequest -> searchRequest.index("index_person") .size(0) .aggregations("agg_01", agg -> agg.avg(avg -> // 聚合的字段 avg.field("age") // 如果聚合的文档缺失这个字段，则给10 .missing(10) ) ) ); System.out.println("request: " + request); SearchResponse response = client.search(request, String.class); System.out.println("response: " + response);} 3.4 min最小值3.4.1 dslPOST /index_person/_search{ "size": 0, "query": { "match_all": {} }, "aggs": { "agg_01": { "sum": { "field": "age", "missing": 10 } } }}3.4.2 java@Test@DisplayName("求和聚合")public void test01() throws IOException { SearchRequest request = SearchRequest.of(searchRequest -> searchRequest.index("index_person") .size(0) .aggregations("agg_01", agg -> agg.sum(sum -> // 聚合的字段 sum.field("age") // 如果聚合的文档缺失这个字段，则给10 .missing(10) ) ) ); System.out.println("request: " + request); SearchResponse response = client.search(request, String.class); System.out.println("response: " + response);} 3.5 count(*)3.5.1 dslPOST /index_person/_search{ "size": 0, "query": { "match_all": {} }, "aggs": { "agg_01": { "value_count": { "field": "province", "missing": 10 } } }}3.5.2 java@Test@DisplayName("count(*)聚合")public void test01() throws IOException { SearchRequest request = SearchRequest.of(searchRequest -> searchRequest.index("index_person") .size(0) .aggregations("agg_01", agg -> agg.valueCount(valueCount -> // 聚合的字段 valueCount.field("age") // 如果聚合的文档缺失这个字段，则给10 .missing(10) ) ) ); System.out.println("request: " + request); SearchResponse response = client.search(request, String.class); System.out.println("response: " + response);} 3.6 count(distinct)3.6.1 dslPOST /index_person/_search{ "size": 0, "query": { "match_all": {} }, "aggs": { "agg_01": { "cardinality": { "field": "province", "missing": 10 } } }}3.6.2 java@Test@DisplayName("count(distinct)聚合")public void test01() throws IOException { SearchRequest request = SearchRequest.of(searchRequest -> searchRequest.index("index_person") .size(0) .aggregations("agg_01", agg -> agg.cardinality(cardinality -> // 聚合的字段 cardinality.field("province") // 如果聚合的文档缺失这个字段，则给10 .missing(10) ) ) ); System.out.println("request: " + request); SearchResponse response = client.search(request, String.class); System.out.println("response: " + response);} 3.7 stat (max,min,avg,count,sum)3.7.1 dslPOST /index_person/_search{ "size": 0, "query": { "match_all": {} }, "aggs": { "agg_01": { "stats": { "field": "avg", "missing": 10 } } }}3.7.2 java@Test@DisplayName("stat聚合")public void test01() throws IOException { SearchRequest request = SearchRequest.of(searchRequest -> searchRequest.index("index_person") .size(0) .aggregations("agg_01", agg -> agg.stats(stats -> // 聚合的字段 stats.field("age") // 如果聚合的文档缺失这个字段，则给10 .missing(10) ) ) ); System.out.println("request: " + request); SearchResponse response = client.search(request, String.class); System.out.println("response: " + response);} 3.8 聚合后返回每个聚合涉及的文档3.8.1 需求根据province进行terms聚合，然后获取每个terms聚合age最大的那个文档。
3.8.2 dslPOST /index_person/_search{ "size": 0, "query": { "range": { "age": { "gte": 10 } } }, "aggs": { "agg_01": { "terms": { "field": "province" }, "aggs": { "agg_02": { "top_hits": { "from": 0, "size": 1, "sort": [ { "age": {"order": "desc"} } ], "_source": { "includes": ["id","age","name"] } } } } } }}3.8.3 java@Test@DisplayName("top hits 聚合")public void test01() throws IOException { SearchRequest request = SearchRequest.of(searchRequest -> searchRequest.index("index_person") .size(0) .query(query -> query.range(range -> range.field("age").gt(JsonData.of(10)))) .aggregations("agg_01", agg -> agg.terms(terms -> terms.field("province") ) .aggregations("agg_02", subAgg -> subAgg.topHits(topHits -> topHits.from(0) .size(1) .sort(sort -> sort.field(field -> field.field("age").order(SortOrder.Desc))) .source(source -> source.filter(filter -> filter.includes(Arrays.asList("id", "age", "name")))) ) ) ) ); System.out.println("request: " + request); SearchResponse response = client.search(request, String.class); System.out.println("response: " + response);} 3.8.4 运行结果运行结果
4、完整代码https://gitee.com/huan1993/spring-cloud-parent/tree/master/es/es8-api/src/main/java/com/huan/es8/aggregations/metric
5、参考文档1、https://www.elastic.co/guide/en/elasticsearch/reference/7.17/search-aggregations-metrics-max-aggregation.html
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