知识点：
1、query string search 2、query DSL 3、query filter 4、full-text search 5、phrase search 6、highlight search
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1、query string search
搜索全部商品：GET /ecommerce/product/_search
took：耗费了几毫秒 timed_out：是否超时，这里是没有 _shards：数据拆成了5个分片，所以对于搜索请求，会打到所有的primary shard（或者是它的某个replica shard也可以） hits.total：查询结果的数量，3个document hits.max_score：score的含义，就是document对于一个search的相关度的匹配分数，越相关，就越匹配，分数也高 hits.hits：包含了匹配搜索的document的详细数据
{ "took": 2, "timed_out": false, "_shards": { "total": 5, "successful": 5, "failed": 0 }, "hits": { "total": 3, "max_score": 1, "hits": [ { "_index": "ecommerce", "_type": "product", "_id": "2", "_score": 1, "_source": { "name": "jiajieshi yagao", "desc": "youxiao fangzhu", "price": 25, "producer": "jiajieshi producer", "tags": [ "fangzhu" ] } }, { "_index": "ecommerce", "_type": "product", "_id": "1", "_score": 1, "_source": { "name": "gaolujie yagao", "desc": "gaoxiao meibai", "price": 30, "producer": "gaolujie producer", "tags": [ "meibai", "fangzhu" ] } }, { "_index": "ecommerce", "_type": "product", "_id": "3", "_score": 1, "_source": { "name": "zhonghua yagao", "desc": "caoben zhiwu", "price": 40, "producer": "zhonghua producer", "tags": [ "qingxin" ] } } ] } }
query string search的由来，因为search参数都是以http请求的query string来附带的
搜索商品名称中包含yagao的商品，而且按照售价降序排序：GET /ecommerce/product/_search?q=name:yagao&sort=price:desc
适用于临时的在命令行使用一些工具，比如curl，快速的发出请求，来检索想要的信息；但是如果查询请求很复杂，是很难去构建的 在生产环境中，几乎很少使用query string search
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2、query DSL
DSL：Domain Specified Language，特定领域的语言 http request body：请求体，可以用json的格式来构建查询语法，比较方便，可以构建各种复杂的语法，比query string search肯定强大多了
查询所有的商品
GET /ecommerce/product/_search { "query": { "match_all": {} } }
查询名称包含yagao的商品，同时按照价格降序排序
GET /ecommerce/product/_search { "query" : { "match" : { "name" : "yagao" } }, "sort": [ { "price": "desc" } ] }
分页查询商品，总共3条商品，假设每页就显示1条商品，现在显示第2页，所以就查出来第2个商品
GET /ecommerce/product/_search { "query": { "match_all": {} }, "from": 1, "size": 1 }
指定要查询出来商品的名称和价格就可以
GET /ecommerce/product/_search { "query": { "match_all": {} }, "_source": ["name", "price"] }
更加适合生产环境的使用，可以构建复杂的查询
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3、query filter
搜索商品名称包含yagao，而且售价大于25元的商品
GET /ecommerce/product/_search { "query" : { "bool" : { "must" : { "match" : { "name" : "yagao" } }, "filter" : { "range" : { "price" : { "gt" : 25 } } } } } }
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4、full-text search（全文检索）
GET /ecommerce/product/_search { "query" : { "match" : { "producer" : "yagao producer" } } }
producer这个字段，会先被拆解，建立倒排索引
special 4 yagao 4 producer 1,2,3,4 gaolujie 1 zhognhua 3 jiajieshi 2
yagao producer ---> yagao和producer
{ "took": 4, "timed_out": false, "_shards": { "total": 5, "successful": 5, "failed": 0 }, "hits": { "total": 4, "max_score": 0.70293105, "hits": [ { "_index": "ecommerce", "_type": "product", "_id": "4", "_score": 0.70293105, "_source": { "name": "special yagao", "desc": "special meibai", "price": 50, "producer": "special yagao producer", "tags": [ "meibai" ] } }, { "_index": "ecommerce", "_type": "product", "_id": "1", "_score": 0.25811607, "_source": { "name": "gaolujie yagao", "desc": "gaoxiao meibai", "price": 30, "producer": "gaolujie producer", "tags": [ "meibai", "fangzhu" ] } }, { "_index": "ecommerce", "_type": "product", "_id": "3", "_score": 0.25811607, "_source": { "name": "zhonghua yagao", "desc": "caoben zhiwu", "price": 40, "producer": "zhonghua producer", "tags": [ "qingxin" ] } }, { "_index": "ecommerce", "_type": "product", "_id": "2", "_score": 0.1805489, "_source": { "name": "jiajieshi yagao", "desc": "youxiao fangzhu", "price": 25, "producer": "jiajieshi producer", "tags": [ "fangzhu" ] } } ] } }
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5、phrase search（短语搜索）
跟全文检索相对应，相反，全文检索会将输入的搜索串拆解开来，去倒排索引里面去一一匹配，只要能匹配上任意一个拆解后的单词，就可以作为结果返回 phrase search，要求输入的搜索串，必须在指定的字段文本中，完全包含一模一样的，才可以算匹配，才能作为结果返回
GET /ecommerce/product/_search { "query" : { "match_phrase" : { "producer" : "yagao producer" } } }
{ "took": 11, "timed_out": false, "_shards": { "total": 5, "successful": 5, "failed": 0 }, "hits": { "total": 1, "max_score": 0.70293105, "hits": [ { "_index": "ecommerce", "_type": "product", "_id": "4", "_score": 0.70293105, "_source": { "name": "special yagao", "desc": "special meibai", "price": 50, "producer": "special yagao producer", "tags": [ "meibai" ] } } ] } }
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6、highlight search（高亮搜索结果）
GET /ecommerce/product/_search { "query" : { "match" : { "producer" : "producer" } }, "highlight": { "fields" : { "producer" : {} } } }
