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过滤查询,其实准确来说,ES中的查询操作分为2种: 查询(query)
和过滤(filter)
。查询即是之前提到的query查询
,它 (查询)默认会计算每个返回文档的得分,然后根据得分排序。而过滤(filter)
只会筛选出符合的文档,并不计算 得分,而且它可以缓存文档 。所以,单从性能考虑,过滤比查询更快。 换句话说过滤适合在大范围筛选数据,而查询则适合精确匹配数据。一般应用时, 应先使用过滤操作过滤数据, 然后使用查询匹配数据。
GET /ems/emp/_search
{
"query": {
"bool": {
"must": [
{"match_all": {}} //查询条件
],
"filter": {....} //过滤条件
}
}
注意:
常见过滤类型有: term 、 terms 、ranage、exists、ids等filter。
GET /ems/emp/_search # 使用term过滤 { "query": { "bool": { "must": [ {"term": { "name": { "value": "小黑" } }} ], "filter": { "term": { "content":"框架" } } } } } GET /dangdang/book/_search #使用terms过滤 { "query": { "bool": { "must": [ {"term": { "name": { "value": "中国" } }} ], "filter": { "terms": { "content":[ "科技", "声音" ] } } } } }
GET /ems/emp/_search { "query": { "bool": { "must": [ {"term": { "name": { "value": "中国" } }} ], "filter": { "range": { "age": { "gte": 7, "lte": 20 } } } } } }
过滤存在指定字段,获取字段不为空的索引记录使用
GET /ems/emp/_search { "query": { "bool": { "must": [ {"term": { "name": { "value": "中国" } }} ], "filter": { "exists": { "field":"aaa" } } } } }
过滤含有指定字段的索引记录
GET /ems/emp/_search { "query": { "bool": { "must": [ {"term": { "name": { "value": "中国" } }} ], "filter": { "ids": { "values": ["1","2","3"] } } } } }
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-elasticsearch</artifactId>
</dependency>
@Data
@Configuration
public class RestClientConfig extends AbstractElasticsearchConfiguration {
@Value("${es.host}")
private String ES_HOST;
@Override
@Bean
public RestHighLevelClient elasticsearchClient() {
final ClientConfiguration clientConfiguration = ClientConfiguration.builder()
.connectedTo(ES_HOST)
.build();
return RestClients.create(clientConfiguration).rest();
}
}
es默认开放了两个端口进行访问,一个是9200的rest方式访问,一个是9300的tcp方式访问,这里推荐使用9200rest方式的访问
相关注解
@Data
@Document(indexName = "products", createIndex = true)
public class Product {
@Id
private Integer id;
@Field(type = FieldType.Keyword)
private String title;
@Field(type = FieldType.Float)
private Double price;
@Field(type = FieldType.Text)
private String description;
}
//1. @Document(indexName = "products", createIndex = true) 用在类上 作用:代表一个对象为一个文档
-- indexName属性: 创建索引的名称
-- createIndex属性: 是否创建索引
//2. @Id 用在属性上 作用:将对象id字段与ES中文档的_id对应
//3. @Field(type = FieldType.Keyword) 用在属性上 作用:用来描述属性在ES中存储类型以及分词情况
-- type: 用来指定字段类型
@Test
public void testCreate() throws IOException {
Product product = new Product();
product.setId(1); //存在id指定id 不存在id自动生成id
product.setTitle("怡宝矿泉水");
product.setPrice(129.11);
product.setDescription("我们喜欢喝矿泉水....");
//文档不存在会创建文档,文档存在会更新文档
elasticsearchOperations.save(product);
}
@Test
public void testDelete() {
Product product = new Product();
product.setId(1);
String delete = elasticsearchOperations.delete(product);
System.out.println(delete);
}
@Test
public void testGet() {
Product product = elasticsearchOperations.get("1", Product.class);
System.out.println(product);
}
@Test
public void testUpdate() {
Product product = new Product();
product.setId(1);
product.setTitle("怡宝矿泉水");
product.setPrice(129.11);
product.setDescription("我们喜欢喝矿泉水,你们喜欢吗....");
elasticsearchOperations.save(product);//不存在添加,存在更新
}
@Test
public void testDeleteAll() {
elasticsearchOperations.delete(Query.findAll(), Product.class);
}
@Test
public void testFindAll() {
SearchHits<Product> productSearchHits = elasticsearchOperations.search(Query.findAll(), Product.class);
productSearchHits.forEach(productSearchHit -> {
System.out.println("id: " + productSearchHit.getId());
System.out.println("score: " + productSearchHit.getScore());
Product product = productSearchHit.getContent();
System.out.println("product: " + product);
});
}
@Test public void testCreateIndex() throws IOException { CreateIndexRequest createIndexRequest = new CreateIndexRequest("fruit"); createIndexRequest.mapping("{\n" + " \"properties\": {\n" + " \"title\":{\n" + " \"type\": \"keyword\"\n" + " },\n" + " \"price\":{\n" + " \"type\": \"double\"\n" + " },\n" + " \"created_at\":{\n" + " \"type\": \"date\"\n" + " },\n" + " \"description\":{\n" + " \"type\": \"text\"\n" + " }\n" + " }\n" + " }\n" , XContentType.JSON); CreateIndexResponse createIndexResponse = restHighLevelClient.indices().create(createIndexRequest, RequestOptions.DEFAULT); System.out.println(createIndexResponse.isAcknowledged()); restHighLevelClient.close(); }
@Test
public void testIndex() throws IOException {
IndexRequest indexRequest = new IndexRequest("fruit");
indexRequest.source("{\n" +
" \"id\" : 1,\n" +
" \"title\" : \"蓝月亮\",\n" +
" \"price\" : 123.23,\n" +
" \"description\" : \"这个洗衣液非常不错哦!\"\n" +
" }",XContentType.JSON);
IndexResponse index = restHighLevelClient.index(indexRequest, RequestOptions.DEFAULT);
System.out.println(index.status());
}
@Test
public void testUpdate() throws IOException {
UpdateRequest updateRequest = new UpdateRequest("fruit","qJ0R9XwBD3J1IW494-Om");
updateRequest.doc("{\"title\":\"好月亮\"}",XContentType.JSON);
UpdateResponse update = restHighLevelClient.update(updateRequest, RequestOptions.DEFAULT);
System.out.println(update.status());
}
@Test
public void testDelete() throws IOException {
DeleteRequest deleteRequest = new DeleteRequest("fruit","1");
DeleteResponse delete = restHighLevelClient.delete(deleteRequest, RequestOptions.DEFAULT);
System.out.println(delete.status());
}
@Test
public void testGet() throws IOException {
GetRequest getRequest = new GetRequest("fruit","aPbmV38BvtuRfHsTIvNo");
GetResponse getResponse = restHighLevelClient.get(getRequest, RequestOptions.DEFAULT);
System.out.println(getResponse.getSourceAsString());
}
public void commonExampleSearch(String indice, QueryBuilder queryBuilder) throws IOException { SearchRequest searchRequest = new SearchRequest(indice); SearchSourceBuilder sourceBuilder=new SearchSourceBuilder(); sourceBuilder.query(queryBuilder); searchRequest.source(sourceBuilder); SearchResponse searchResponse = restHighLevelClient.search(searchRequest, RequestOptions.DEFAULT); System.out.println("总记录数: "+searchResponse.getHits().getTotalHits().value); System.out.println("最大得分: "+searchResponse.getHits().getMaxScore()); SearchHit[] hits = searchResponse.getHits().getHits(); for (SearchHit hit : hits) { System.out.println(hit.getSourceAsString()); } } @Test public void testSearch() throws IOException { String indice="fruit"; //查询所有 commonExampleSearch(indice,QueryBuilders.matchAllQuery()); //term查询 commonExampleSearch(indice,QueryBuilders.termQuery("description","不错哦!")); //prefix查询 commonExampleSearch(indice,QueryBuilders.prefixQuery("description","这个")); //通配符查询 commonExampleSearch(indice,QueryBuilders.wildcardQuery("title","好*")); //ids查询--多id查询 commonExampleSearch(indice,QueryBuilders.idsQuery().addIds("1","2")); //多字段查询 commonExampleSearch(indice,QueryBuilders.multiMatchQuery("不错","title","description")); }
@Test public void testSearch1() throws IOException { SearchRequest searchRequest = new SearchRequest("fruit"); SearchSourceBuilder sourceBuilder = new SearchSourceBuilder(); sourceBuilder //分页查询 .from(0)//起始位置 start=(page-1)*size .size(2)//每页显示条数,默认返回10条 //指定排序字段,参数一:根据哪个字段进行排序,参数二:排序方式 .sort("price", SortOrder.DESC) //返回的结果中排除或者包含哪些字段 //参数1:包含的字段数组 //参数2:排除字段数组 .fetchSource(new String[]{"title"},new String[]{}) //高亮设置 .highlighter(new HighlightBuilder() //高亮显示的字段 .field("description") //多字段高亮开启 .requireFieldMatch(false) //自定义高亮html标签 .preTags("<span style='color:red;'>").postTags("</span>")) //查询 .query(QueryBuilders.termQuery("description","错")); searchRequest.source(sourceBuilder); SearchResponse searchResponse = restHighLevelClient.search(searchRequest, RequestOptions.DEFAULT); System.out.println("总条数: "+searchResponse.getHits().getTotalHits().value); SearchHit[] hits = searchResponse.getHits().getHits(); for (SearchHit hit : hits) { System.out.println(hit.getSourceAsString()); //显示当前查询结果中出现的高亮字段 Map<String, HighlightField> highlightFields = hit.getHighlightFields(); highlightFields.forEach((k,v)-> System.out.println("key: "+k + " value: "+v.fragments()[0])); } }
/** * query: 精确查询,查询计算文档得分,并根据文档得分进行返回 * filter query: 过滤查询,用来在大量数据中筛选出本地查询相关数据,不会计算文档得分,经常使用filter query结果进行缓存 * 注意: 一旦使用query和filterQuery es优先执行filter query 然后再执行 query */ @Test public void testFilterQuery() throws IOException { SearchRequest searchRequest=new SearchRequest("fruit"); SearchSourceBuilder sourceBuilder=new SearchSourceBuilder(); sourceBuilder.query(QueryBuilders.termQuery("description","不错")) //指定过滤条件 .postFilter(QueryBuilders.idsQuery().addIds("1","2","3")); searchRequest.source(sourceBuilder); SearchResponse searchResponse = restHighLevelClient.search(searchRequest, RequestOptions.DEFAULT); System.out.println("符合条件的总数为: "+searchResponse.getHits().getTotalHits().value); }
ElasticsearchOperations面向对象的查询方式,有其优点所在,那么我们能否将其和RestHighLevelClient 进行互补呢 ?
看下面的例子:
@AllArgsConstructor
@NoArgsConstructor
@Builder
@Data
public class Fruit implements Serializable {
private String title;
private Double price;
private Date create_at;
private String description;
}
/** * @author 大忽悠 * @create 2022/3/5 11:34 */ public class AllTest extends EsApplicationTests{ ObjectMapper objectMapper=new ObjectMapper(); /** * 添加文档 */ @Test public void addIndice() throws IOException { Fruit fruit = Fruit.builder().id(5).title("大忽悠").price(520.521) .description("大忽悠喜欢小朋友") .build(); IndexRequest indexRequest=new IndexRequest("fruit"); indexRequest.id(fruit.getId().toString()).source(objectMapper.writeValueAsString(fruit),XContentType.JSON); IndexResponse index = restHighLevelClient.index(indexRequest, RequestOptions.DEFAULT); System.out.println(index.status()); } public void commonExampleSearch(String indice, QueryBuilder queryBuilder) throws IOException { SearchRequest searchRequest = new SearchRequest(indice); SearchSourceBuilder sourceBuilder=new SearchSourceBuilder(); sourceBuilder.query(queryBuilder); searchRequest.source(sourceBuilder); SearchResponse searchResponse = restHighLevelClient.search(searchRequest, RequestOptions.DEFAULT); System.out.println("总记录数: "+searchResponse.getHits().getTotalHits().value); System.out.println("最大得分: "+searchResponse.getHits().getMaxScore()); SearchHit[] hits = searchResponse.getHits().getHits(); for (SearchHit hit : hits) { System.out.println("返回的结果为: "+hit.getSourceAsString()); //JSON格式转换 Fruit fruit = objectMapper.readValue(hit.getSourceAsString(), Fruit.class); System.out.println("得到的结果为: "+fruit); } } /** * 查询全部 */ @Test public void searchAll() throws IOException { String indice="fruit"; //查询所有 commonExampleSearch(indice, QueryBuilders.matchAllQuery()); } }
注意: 两者的区别,因此我们在上传文档的时候,一定要通过objectMapper.writeValueAsString(fruit)的方式先转换为JSON串的原因
Fruit fruit = Fruit.builder().id(5).title("大忽悠").price(520.521)
.description("大忽悠喜欢小朋友")
.build();
System.out.println(objectMapper.writeValueAsString(fruit));
System.out.println(fruit);
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