聊聊Elasticsearch之Metric聚合
作者：huan1993
此篇文章簡單的記錄一下 elasticsearch的metric聚合操作。比如求 平均值、最大值、最小值、求和、總計、去重總計等。
1、背景
此篇文章簡單的記錄一下 elasticsearch的metric聚合操作。比如求 平均值、最大值、最小值、求和、總計、去重總計等。
2、準備數據
2.1 準備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 準備數據
PUT /index_person/_bulk
{"index":{"_id":1}}
{"id":1, "name":"張三","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":"趙六","age":21,"class":"大三班技術班","province":"北京"}
{"index":{"_id":5}}
{"id":5, "name":"錢七","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代碼
@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")
// 如果聚合的文檔缺失這個字段，則給10
.missing(10)
)
)
);
System.out.println("request: " + request);
SearchResponse<String> response = client.search(request, String.class);
System.out.println("response: " + response);
}
@Test
@DisplayName("腳本聚合")
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)
// 腳本表達式
.source("doc.age")
)
)
)
)
);
System.out.println("request: " + request);
SearchResponse<String> response = client.search(request, String.class);
System.out.println("response: " + response);
}
@Test
@DisplayName("值腳本聚合")
public void test03() throws IOException {
SearchRequest request = SearchRequest.of(searchRequest ->
searchRequest.index("index_person")
.size(0)
.aggregations("agg_01", agg ->
agg.max(max ->
// 指定參與聚合的字段
max.field("age")
.script(script ->
script.inline(inline ->
inline.lang(ScriptLanguage.Painless)
// 腳本表達式
.source("_value * params.plus")
// 參數
.params("plus", JsonData.of(2))
)
)
)
)
);
System.out.println("request: " + request);
SearchResponse<String> 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")
// 如果聚合的文檔缺失這個字段，則給10
.missing(10)
)
)
);
System.out.println("request: " + request);
SearchResponse<String> 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")
// 如果聚合的文檔缺失這個字段，則給10
.missing(10)
)
)
);
System.out.println("request: " + request);
SearchResponse<String> 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")
// 如果聚合的文檔缺失這個字段，則給10
.missing(10)
)
)
);
System.out.println("request: " + request);
SearchResponse<String> 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")
// 如果聚合的文檔缺失這個字段，則給10
.missing(10)
)
)
);
System.out.println("request: " + request);
SearchResponse<String> 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")
// 如果聚合的文檔缺失這個字段，則給10
.missing(10)
)
)
);
System.out.println("request: " + request);
SearchResponse<String> response = client.search(request, String.class);
System.out.println("response: " + response);
}
3.8 聚合后返回每個聚合涉及的文檔
3.8.1 需求
根據 province進行terms聚合，然后獲取每個terms聚合 age最大的那個文檔。
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<String> response = client.search(request, String.class);
System.out.println("response: " + response);
}
3.8.4 運行結果
運行結果
4、完整代碼
https://gitee.com/huan1993/spring-cloud-parent/tree/master/es/es8-api/src/main/java/com/huan/es8/aggregations/metric
5、參考文檔
1、https://www.elastic.co/guide/en/elasticsearch/reference/7.17/search-aggregations-metrics-max-aggregation.html
責任編輯：武曉燕
來源：
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