(资料图)

1、背景

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mapping
PUT /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 dsl
POST /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 dsl
POST /index_person/_search{  "size": 0,  "query": {    "match_all": {}  },  "aggs": {    "agg_01": {      "min": {        "field": "age",        "missing": 10      }    }  }}
3.2.2 java
POST /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 dsl
POST /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 dsl
POST /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 dsl
POST /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 dsl
POST /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 dsl
POST /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 dsl
POST /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

推荐内容