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
结果是：
{"took": 5,"timed_out": false,"_shards": {"total": 5,"successful": 5,"failed": 0},"hits": {"total": 3,"max_score": null,"hits": [{"_index": "ecommerce","_type": "product","_id": "3","_score": null,"_source": {"name": "zhonghua yagao","desc": "caoben zhiwu","price": 40,"producer": "zhonghua producer","tags": ["qingxin"]},"sort": [40]},{"_index": "ecommerce","_type": "product","_id": "1","_score": null,"_source": {"name": "jiaqiangban gaoluejie yagao","desc": "gaoxiao meibai","price": 30,"producer": "gaolujie producer","tags": ["meibai","fangzhu"]},"sort": [30]},{"_index": "ecommerce","_type": "product","_id": "2","_score": null,"_source": {"name": "jiajieshi yagao","desc": "youxiao fangzhu","price": 25,"producer": "jiajieshi producer","tags": ["fangzhu"]},"sort": [25]}]}}
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
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": {} }}
结果是：
{"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": "jiaqiangban gaoluejie 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"]}}]}}
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" }]}
结果是：
{"took": 3,"timed_out": false,"_shards": {"total": 5,"successful": 5,"failed": 0},"hits": {"total": 1,"max_score": null,"hits": [{"_index": "ecommerce","_type": "product","_id": "3","_score": null,"_source": {"name": "zhonghua yagao","desc": "caoben zhiwu","price": 40,"producer": "zhonghua producer","tags": ["qingxin"]},"sort": [40]}]}}
如果在查询的时候报如下错误：
{"error": {"root_cause": [{"type": "illegal_argument_exception","reason": "Fielddata is disabled on text fields by default. Set fielddata=true on [price] in order to load fielddata in memory by uninverting the inverted index. Note that this can however use significant memory. Alternatively use a keyword field instead."}],"type": "search_phase_execution_exception","reason": "all shards failed","phase": "query","grouped": true,"failed_shards": [{"shard": 0,"index": "ecommerce","node": "DEtgiaiTSaWWvmOfvlvc6Q","reason": {"type": "illegal_argument_exception","reason": "Fielddata is disabled on text fields by default. Set fielddata=true on [price] in order to load fielddata in memory by uninverting the inverted index. Note that this can however use significant memory. Alternatively use a keyword field instead."}}]},"status": 400}
解决办法是（其中语法是：/type/_mapping/index）,然后添加fielddata属性：
PUT /ecommerce/_mapping/product {"properties": {"price":{"type": "text","fielddata": true}}}
执行完成之后：
{"acknowledged": true}
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}
结果是：
{"took": 4,"timed_out": false,"_shards": {"total": 5,"successful": 5,"failed": 0},"hits": {"total": 3,"max_score": 1,"hits": [{"_index": "ecommerce","_type": "product","_id": "1","_score": 1,"_source": {"name": "jiaqiangban gaoluejie yagao","desc": "gaoxiao meibai","price": 30,"producer": "gaolujie producer","tags": ["meibai","fangzhu"]}}]}}
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"]}
结果是：
{"took": 3,"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": {"price": 25,"name": "jiajieshi yagao"}},{"_index": "ecommerce","_type": "product","_id": "1","_score": 1,"_source": {"price": 30,"name": "jiaqiangban gaoluejie yagao"}},{"_index": "ecommerce","_type": "product","_id": "3","_score": 1,"_source": {"price": 40,"name": "zhonghua yagao"}}]}}
更加适合生产环境的使用，可以构建复杂的查询
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 } }}}}}
结果是：
{"took": 68,"timed_out": false,"_shards": {"total": 5,"successful": 5,"failed": 0},"hits": {"total": 2,"max_score": 0.25811607,"hits": [{"_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": "1","_score": 0.25316024,"_source": {"name": "jiaqiangban gaoluejie yagao","desc": "gaoxiao meibai","price": 30,"producer": "gaolujie producer","tags": ["meibai","fangzhu"]}}]}}
4、full-text search（全文检索）
先添加一条记录：
put /ecommerce/product/4{"name":"special yagao","desc":"special meibai","price":50,"producer":"special yagao producer","tags":["meibai"]}
进行查询
GET /ecommerce/product/_search{"query" : {"match" : {"producer" : "yagao producer"}}}
上面的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
也就是说yagao producer 会被拆解成： yagao和producer，最后查询出来的结果是：
{"took": 4,"timed_out": false,"_shards": {"total": 5,"successful": 5,"failed": 0},"hits": {"total": 4,"max_score": 0.25811607,"hits": [{"_index": "ecommerce","_type": "product","_id": "1","_score": 0.25811607,"_source": {"name": "jiaqiangban gaoluejie 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"]}},{"_index": "ecommerce","_type": "product","_id": "4","_score": 0.14638957,"_source": {"name": "special yagao","desc": "special meibai","price": 50,"producer": "special yagao producer","tags": ["meibai"]}}]}}
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"}}}
搜索到的结果是：
{"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"]}}]}}
6、highlight search（高亮搜索结果）
GET /ecommerce/product/_search{"query" : {"match" : {"producer" : "producer"}},"highlight": {"fields" : {"producer" : {}}}}
查询出来的结果是：
{"took": 50,"timed_out": false,"_shards": {"total": 5,"successful": 5,"failed": 0},"hits": {"total": 4,"max_score": 0.25811607,"hits": [{"_index": "ecommerce","_type": "product","_id": "1","_score": 0.25811607,"_source": {"name": "jiaqiangban gaoluejie yagao","desc": "gaoxiao meibai","price": 30,"producer": "gaolujie producer","tags": ["meibai","fangzhu"]},"highlight": {"producer": ["gaolujie <em>producer</em>"]}},{"_index": "ecommerce","_type": "product","_id": "3","_score": 0.25811607,"_source": {"name": "zhonghua yagao","desc": "caoben zhiwu","price": 40,"producer": "zhonghua producer","tags": ["qingxin"]},"highlight": {"producer": ["zhonghua <em>producer</em>"]}},{"_index": "ecommerce","_type": "product","_id": "2","_score": 0.1805489,"_source": {"name": "jiajieshi yagao","desc": "youxiao fangzhu","price": 25,"producer": "jiajieshi producer","tags": ["fangzhu"]},"highlight": {"producer": ["jiajieshi <em>producer</em>"]}},{"_index": "ecommerce","_type": "product","_id": "4","_score": 0.14638957,"_source": {"name": "special yagao","desc": "special meibai","price": 50,"producer": "special yagao producer","tags": ["meibai"]},"highlight": {"producer": ["special yagao <em>producer</em>"]}}]}}
