7.3.6 multi Query
上边学习的termQuery和matchQuery一次只能匹配一个Field,本节学习multiQuery,一次可以匹配多个字段。
1、基本使用
单项匹配是在一个field中去匹配,多项匹配是拿关键字去多个Field中匹配。
例子:
发送:post http://localhost:9200/xc_course/doc/_search
拿关键字 “spring css”去匹配name 和description字段。
{
"query": {
"multi_match" : {
"query" : "spring css",
"minimum_should_match": "50%",
"fields": [ "name", "description" ]
}
}
}
搜索结果
{
"took": 112,
"timed_out": false,
"_shards": {
"total": 1,
"successful": 1,
"skipped": 0,
"failed": 0
},
"hits": {
"total": 2,
"max_score": 1.3339276,
"hits": [
{
"_index": "xc_course",
"_type": "doc",
"_id": "3",
"_score": 1.3339276,
"_source": {
"name": "spring开发基础",
"description": "spring 在java领域非常流行,java程序员都在用。",
"studymodel": "201001",
"price": 88.6,
"timestamp": "2018-02-24 19:11:35",
"pic": "group1/M00/00/00/wKhlQFs6RCeAY0pHAAJx5ZjNDEM428.jpg"
}
},
{
"_index": "xc_course",
"_type": "doc",
"_id": "1",
"_score": 0.69607234,
"_source": {
"name": "Bootstrap开发",
"description": "Bootstrap是由Twitter推出的一个前台页面开发框架,是一个非常流行的开发框架,此框架集成了多种页面效果。此开发框架包含了大量的CSS、JS程序代码,可以帮助开发者(尤其是不擅长页面开发的程序人员)轻松的实现一个不受浏览器限制的精美界面效果。",
"studymodel": "201002",
"price": 38.6,
"timestamp": "2018-04-25 19:11:35",
"pic": "group1/M00/00/00/wKhlQFs6RCeAY0pHAAJx5ZjNDEM428.jpg"
}
}
]
}
}
第1篇文章得分"_score": 1.3339276,
第2篇文章得分 “_score”: 0.69607234,
为何第1篇文章得分比第2篇文章高,因为第1篇文章出现搜索关键词的次数比第2篇文章出现次数多,所以得分高,排名靠前
2、提升boost
匹配多个字段时可以提升字段的boost(权重)来提高得分
例子:
提升boost之前,执行下边的查询:
{
"query": {
"multi_match" : {
"query" : "spring框架",
"minimum_should_match": "50%",
"fields": [ "name", "description" ]
}
}
}
搜索结果:
{
"took": 14,
"timed_out": false,
"_shards": {
"total": 1,
"successful": 1,
"skipped": 0,
"failed": 0
},
"hits": {
"total": 2,
"max_score": 1.4149667,
"hits": [
{
"_index": "xc_course",
"_type": "doc",
"_id": "1",
"_score": 1.4149667,
"_source": {
"name": "Bootstrap开发",
"description": "Bootstrap是由Twitter推出的一个前台页面开发框架,是一个非常流行的开发框架,此框架集成了多种页面效果。此开发框架包含了大量的CSS、JS程序代码,可以帮助开发者(尤其是不擅长页面开发的程序人员)轻松的实现一个不受浏览器限制的精美界面效果。",
"studymodel": "201002",
"price": 38.6,
"timestamp": "2018-04-25 19:11:35",
"pic": "group1/M00/00/00/wKhlQFs6RCeAY0pHAAJx5ZjNDEM428.jpg"
}
},
{
"_index": "xc_course",
"_type": "doc",
"_id": "3",
"_score": 1.3339276,
"_source": {
"name": "spring开发基础",
"description": "spring 在java领域非常流行,java程序员都在用。",
"studymodel": "201001",
"price": 88.6,
"timestamp": "2018-02-24 19:11:35",
"pic": "group1/M00/00/00/wKhlQFs6RCeAY0pHAAJx5ZjNDEM428.jpg"
}
}
]
}
}
因为“框架”这个词在标题为“Bootstrap开发”这篇文章里出现次数 比 “spring”在标题为"spring开发基础"这篇文章里出现的次数多,所以得分高。
但是我想让标题里出现的搜索关键词的文章排名靠前,怎么搜索呢。
提升boost,通常关键字匹配上name的权重要比匹配上description的权重高,这里可以对name的权重提升。
{
"query": {
"multi_match" : {
"query" : "spring框架",
"minimum_should_match": "50%",
"fields": [ "name^10", "description" ]
}
}
}
“name^10” 表示权重提升10倍,执行上边的查询,发现name中包括spring关键字的文档排在前边。
搜索结果:
{
"took": 5,
"timed_out": false,
"_shards": {
"total": 1,
"successful": 1,
"skipped": 0,
"failed": 0
},
"hits": {
"total": 2,
"max_score": 9.331132,
"hits": [
{
"_index": "xc_course",
"_type": "doc",
"_id": "3",
"_score": 9.331132,
"_source": {
"name": "spring开发基础",
"description": "spring 在java领域非常流行,java程序员都在用。",
"studymodel": "201001",
"price": 88.6,
"timestamp": "2018-02-24 19:11:35",
"pic": "group1/M00/00/00/wKhlQFs6RCeAY0pHAAJx5ZjNDEM428.jpg"
}
},
{
"_index": "xc_course",
"_type": "doc",
"_id": "1",
"_score": 1.4149667,
"_source": {
"name": "Bootstrap开发",
"description": "Bootstrap是由Twitter推出的一个前台页面开发框架,是一个非常流行的开发框架,此框架集成了多种页面效果。此开发框架包含了大量的CSS、JS程序代码,可以帮助开发者(尤其是不擅长页面开发的程序人员)轻松的实现一个不受浏览器限制的精美界面效果。",
"studymodel": "201002",
"price": 38.6,
"timestamp": "2018-04-25 19:11:35",
"pic": "group1/M00/00/00/wKhlQFs6RCeAY0pHAAJx5ZjNDEM428.jpg"
}
}
]
}
}
JavaClient:
MultiMatchQueryBuilder multiMatchQueryBuilder = QueryBuilders.multiMatchQuery("spring框架","name", "description").minimumShouldMatch("50%");
multiMatchQueryBuilder.field("name",10);//提升boost
//MultiMatchQuery
@Test
public void testMultiMatchQuery() throws IOException, ParseException {
//搜索请求对象
SearchRequest searchRequest = new SearchRequest("xc_course");
//指定类型
searchRequest.types("doc");
//搜索源构建对象
SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
//搜索方式
//MultiMatchQuery
searchSourceBuilder.query(QueryBuilders.multiMatchQuery("spring css","name","description")
.minimumShouldMatch("50%")
.field("name",10));
//设置源字段过虑,第一个参数结果集包括哪些字段,第二个参数表示结果集不包括哪些字段
searchSourceBuilder.fetchSource(new String[]{"name","studymodel","price","timestamp"},new String[]{});
//向搜索请求对象中设置搜索源
searchRequest.source(searchSourceBuilder);
//执行搜索,向ES发起http请求
SearchResponse searchResponse = client.search(searchRequest);
//搜索结果
SearchHits hits = searchResponse.getHits();
//匹配到的总记录数
long totalHits = hits.getTotalHits();
//得到匹配度高的文档
SearchHit[] searchHits = hits.getHits();
//日期格式化对象
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
for(SearchHit hit:searchHits){
//文档的主键
String id = hit.getId();
//源文档内容
Map<String, Object> sourceAsMap = hit.getSourceAsMap();
String name = (String) sourceAsMap.get("name");
//由于前边设置了源文档字段过虑,这时description是取不到的
String description = (String) sourceAsMap.get("description");
//学习模式
String studymodel = (String) sourceAsMap.get("studymodel");
//价格
Double price = (Double) sourceAsMap.get("price");
//日期
Date timestamp = dateFormat.parse((String) sourceAsMap.get("timestamp"));
System.out.println(name);
System.out.println(studymodel);
System.out.println(description);
}
}