Elasticsearch Java REST高级客户端 parent/child join

迷南。 2024-04-17 14:33 79阅读 0赞

# Elasticsearch Java REST高级客户端  parent/child join #

Elasticsearch 7.2.0

1.数据准备

2.parentId根据父文档id查询相关子文档

3.通过ID和routing ，访问子文档(不加routing查不到)

4.hasChild 返回父文档

5.hasParent 返回相关的子文档

6.Java REST高级客户端连接及关闭

对人工智能感兴趣点下面链接

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[https://www.cbedai.net/u014646662][Link 1]

## 1.数据准备 ##

数据准备见：[https://blog.csdn.net/u014646662/article/details/100081257][https_blog.csdn.net_u014646662_article_details_100081257]

## 2.parentId根据父文档id查询相关子文档 ##

/**
    	 * 根据父文档id查询相关子文档
    	 */
    	private static void parentId() {
    		//客户端连接
    		RestHighLevelClient client = getClient();
    		SearchRequest request = new SearchRequest("my_blogs");
    		SearchSourceBuilder builder = new SearchSourceBuilder();
    		request.source(builder);
    		//子文档名
    		String child_type = "comment";
    		//父文档ID
    		String id = "blog2";
    		//ParentId查询
    		ParentIdQueryBuilder parentIdQueryBuilder = new ParentIdQueryBuilder(child_type, id);
    		builder.query(parentIdQueryBuilder);
    		builder.from(0);
    		builder.size(10);
    
    		try {
    			//提交查询
    			SearchResponse response = client.search(request, RequestOptions.DEFAULT);
    			response.getHits().forEach(System.out::println);
    		} catch (IOException e) {
    			e.printStackTrace();
    		} finally {
    			close(client);
    		}
    	}

## 3.通过ID和routing ，访问子文档(不加routing查不到) ##

这个就是Get查询，不过需要加上路由

/**
    	 * 通过ID和routing ，访问子文档(不加routing查不到)
    	 */
    	private static void childID() {
    		RestHighLevelClient client = getClient();
    		GetRequest getRequest = new GetRequest("my_blogs", "comment3");
    		//必须指定路由（父ID）
    		getRequest.routing("blog2");
    		try {
    			GetResponse getResponse = client.get(getRequest, RequestOptions.DEFAULT);
    			if (getResponse.isExists()) {
    				String sourceAsString = getResponse.getSourceAsString();
    				System.out.println(sourceAsString);
    			} else {
    				System.out.println("未查到结果");
    			}
    		} catch (IOException e) {
    			e.printStackTrace();
    		}finally {
    			close(client);
    		}
    
    	}

## 4.hasChild 返回父文档 ##

/**
    	 * 返回父文档
    	 */
    	private static void hasChild() {
    		RestHighLevelClient client = getClient();
    		SearchRequest request = new SearchRequest("my_blogs");
    		SearchSourceBuilder builder = new SearchSourceBuilder();
    		request.source(builder);
    		// 子文档名
    		String child_type = "comment";
    		// 子文档查询条件
    		QueryBuilder matchQuery = QueryBuilders.matchQuery("comment", "Elastic");
    		// 是否计算评分
    		ScoreMode scoreMode = ScoreMode.Total;
    		HasChildQueryBuilder hasChildQueryBuilder = new HasChildQueryBuilder(child_type, matchQuery, scoreMode);
    		builder.query(hasChildQueryBuilder);
    		builder.from(0);
    		builder.size(10);
    		builder.sort("_score");
    		SearchResponse response = null;
    		try {
    			response = client.search(request, RequestOptions.DEFAULT);
    			response.getHits().forEach(System.out::println);
    		} catch (IOException e) {
    			e.printStackTrace();
    		} finally {
    			close(client);
    		}
    
    	}

## 5.hasParent 返回相关的子文档 ##

/**
    	 * 返回相关的子文档
    	 */
    	private static void hasParent() {
    		RestHighLevelClient client = getClient();
    		SearchRequest request = new SearchRequest("my_blogs");
    		SearchSourceBuilder builder = new SearchSourceBuilder();
    		request.source(builder);
    		// 父文档名
    		String parent_type = "blog";
    		// 子文档查询条件
    		QueryBuilder matchQuery = QueryBuilders.matchQuery("title", "hadoop learning");
    		// 是否计算评分
    		boolean score = true;
    		HasParentQueryBuilder hasParentQueryBuilder = new HasParentQueryBuilder(parent_type, matchQuery, score);
    		builder.query(hasParentQueryBuilder);
    		builder.from(0);
    		builder.size(10);
    		// 按评分排序
    		builder.sort("_score");
    		SearchResponse search = null;
    		try {
    			search = client.search(request, RequestOptions.DEFAULT);
    			search.getHits().forEach(System.out::println);
    		} catch (IOException e) {
    			e.printStackTrace();
    		} finally {
    			close(client);
    		}
    	}

## 6.Java REST高级客户端连接及关闭 ##

REST高级客户端多种方式连接：[https://blog.csdn.net/u014646662/article/details/98966833][https_blog.csdn.net_u014646662_article_details_98966833]

7.以上查询，需要提前指定查询结果的个数，如需要查询全部文档，可以使用SearchScrollApi

SearchScrollApi例子：[https://blog.csdn.net/u014646662/article/details/96993691][https_blog.csdn.net_u014646662_article_details_96993691]

[Link 1]: https://www.cbedai.net/u014646662
[https_blog.csdn.net_u014646662_article_details_100081257]: https://blog.csdn.net/u014646662/article/details/100081257
[https_blog.csdn.net_u014646662_article_details_98966833]: https://blog.csdn.net/u014646662/article/details/98966833
[https_blog.csdn.net_u014646662_article_details_96993691]: https://blog.csdn.net/u014646662/article/details/96993691