IT_arookie的博客

public class EsUtil{ // 删除索引 protected boolean deleteIndies(RestHighLevelClient client, String indexName) throws IOException { DeleteIndexRequest index = new DeleteIndexRequest(indexName); if (existIndies(client, indexName)) {

es7.1聚合查询 javaAPI (三)   es复杂聚合查询 — select a,count(distinct b)     对a分组对b聚合 类似如下sql select a,count(distinct b) as count from myIndex group by a order by count desc limit 5; 核心聚合方法 // 去重聚合 CardinalityAggregationBuilder distinct_count = AggregationBuilde

es7.1聚合查询 javaAPI（二）  按时间聚合 # 类似如下sql select DATE_FORMAT(date,"yyyy-MM-dd") as date,count(1) as count from myIndex where date between '2020-07-01 00:00:00' and '2020-07-10 00:00:00' group by date; // 核心聚合方法 DateHistogramAggregationBuilder days = Agg

查询符合条件的数据量 /** * 查询符合条件的数据量 * * @param client RestHighLevelClient类型的连接对象 * @param queryBuilder 查询限制条件 可以为null * @return long * @throws IOException 查询数据抛出的异常 */ public long getAllCountForOneField(RestHighLevelClient client, QueryBu.

es7.1基本查询 java API 1.随机取15条数据 /** * 1.随机取15条数据(默认10条) * 类似sql如下： * select * from myIndex order by rand() limit 15 * * ShowData ： 返回一条数据的实体类(不做赘述) * getClient(): 获取es查询的连接对象(不做赘述) * 注释: 只能取1万条 */ public List<ShowData> query

es版本 <!--Es连接--> <dependency> <groupId>org.elasticsearch.client</groupId> <artifactId>elasticsearch-rest-high-level-client</artifactId> <version&g...