面向文档的搜索分析引擎
(1)应用系统的数据结构都是面向对象的
(2)对象数据存储到数据库中，只能拆解，变为多张表，查询的时候还要还原为对象格式
(3)ES是面向文档的，与面向对象的数据结构一样，基于文档的数据结构，es可以提供复杂的索引、全文检索、分析聚合等功能
{ "email":"zhangsan@qq.com", "first_name":"san", "last_name":"zhang", "info"{ "bio":"curison and modest","age":30,"interests":["bike","climb"] }, "join_date":"2017-01-01"}2、电商网站商品管理案例背景介绍
(1) 对商品信息进行CRUD（增删改查）
(2)执行简单的结构化查询
(3)可以执行简单的全文检索，以及复杂的phrase(短语)检索
(4)对于全文检索的结构，可以进行高亮显示
(5)对数据进行简单的聚合分析
3、简单的集群管理
(1)快速检查集群的健康状况
get _cat/health?v
epoch timestamp cluster status node.total node.data shards pri relo init unassign pending_tasks max_task_wait_time active_shards_percent
1525610669 20:44:29 elasticsearch green 1 1 0 0 0 0 0 0 - 100.0%
如何快速了解集群的健康状况？green、yellow、red?
green:每个索引的primary shared和replica shared都是active状态的
yellow:每个索引的primary shared都是active的，部分replica shared不是active
red:不是索引的primary shared都是active的，部分索引数据丢失的
(2)快速查看集群中有哪些索引？
get _cat/indices?v
(3)简单的索引操作
创建索引：PUT /test_index?pretty
删除索引：delete /test_index?pretty
4、商品的CRUD操作
(1)新增商品：新建文档、建立索引
PUT /index/type/id
PUT /ecommerce/product/1{ "name":"gaolujie yagao", "desc":"gaoxiao meibai", "price":30, "producer":"gaolujie producer", "tags":["meibai","fangzhu"]}PUT /ecommerce/product/2{ "name":"jiajieshi yagao", "desc":"gaoxiao fangzhu", "price":25, "producer":"jiajieshi producer", "tags":["fangzhu"]}PUT /ecommerce/product/3{ "name":"zhonghua yagao", "desc":"caoben zhiwu", "price":40, "producer":"zhonghua producer", "tags":["qingxin"]}返回结果：
{ "_index": "ecommerce", "_type": "product", "_id": "3", "_version": 1, "result": "created", "_shards": { "total": 2, "successful": 1, "failed": 0 }, "_seq_no": 0, "_primary_term": 1}ES会自动建立index和type，不需要提前创建，而且ES默认会对document每个field都建立倒排索引，让其可以被搜索
(2)查询商品，检索文档
GET /index/type/id
GET /ecommerce/product/2
(3)修改商品，替换文档
PUT /ecommerce/product/1{ "name":"jiaqiangban gaolujie yagao", "desc":"gaoxiao meibai", "price":30, "producer":"gaolujie producer" "tags":["meibai","fangzhu"]}替换方式有一个不好的地方，必须带上所有的field，才能去进行信息修改，否则会丢失数据
(4)修改商品，更新文档
POST /ecommerce/product/1/_update { "doc":{ "name":"jiaqiangban gaolujie yagao" } }(5)删除文档
delete /ecommerce/product/1?pretty
二、ES的查询语法
1、query string search
GET /ecommerce/product/_search GET /ecommerce/product/_search?q=name:yagao&sort=price:desc
{ "took": 54, 耗费的毫秒数 "timed_out": false, 是否超时 "_shards": { "total": 5, 数据被拆成5个分片 "successful": 5, "skipped": 0, "failed": 0 }, hits": { "total": 3, 查询结果的数量，3个document "max_score": 1,search的相关度，越相关，就越匹配，分数就越高 "hits"：包含了搜索的document的详细数据2、query DSl 特定领域的语言
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
GET /ecommerce/product/_search { "query":{"match_all": {}}, "from": 1, "size":1 }指定要查询商品的名称和价格就可以了
GET /ecommerce/product/_search { "query":{"match_all": {}}, "_source": ["name","price"] }query filter
搜索商品名称包含牙膏，而且售价大于25元的商品
GET /ecommerce/product/_search { "query": { "bool": { "must": [ {"match": { "name": "yagao" }} ],"filter": {"range": { "price": { "gte": 30 } }} } } }full-text search
PUT /ecommerce/product/4{ "name":"special yagao", "desc":"special meibai", "price":50, "producer":"special yagao producer", "tags":["meibai"]}GET /ecommerce/product/_search{ "query": {"match": { "producer": "yagao producer" }}}phrase search
跟全文索引相对应，全文索引会将输入的搜索串拆解开来，去倒排索引里面一一匹配，只要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，才算匹配
GET /ecommerce/product/_search{ "query": {"match_phrase": { "producer": "yagao producer" }}}highlight search
GET /ecommerce/product/_search{ "query": {"match": { "producer": "producer" }}, "highlight": {"fields": { "producer": {} }}}三、使用restful api做简单的聚合计算
计算每个tag下的商品数量
GET /ecommerce/product/_search{ "aggs": { "group_by_tags": { "terms": { "field": "tags" } } }}将文本field的fieldata属性设置为TRUE
put /ecommerce/_mapping/product{"properties":{ "tags":{ "type":"text", "fielddata":true }}}GET /ecommerce/product/_search{ "size":0, "aggs": { "group_by_tags": { "terms": { "field": "tags" } } }}对名称中包含yagao的商品，计算每个tag下的商品数量
GET /ecommerce/product/_search{ "size":0, "query": {"match": { "name": "yagao" }}, "aggs": { "group_by_tags": { "terms": { "field": "tags" } } }}先分组，在算每组的平均值，计算每个tag下的商品的平均价格
GET /ecommerce/product/_search{ "size":0, "aggs": { "group_by_tags": { "terms": { "field": "tags" }, "aggs": { "avg_price": { "avg": { "field": "price" } } } } }}计算每个tag下的商品的平均价格，并降序排序
GET /ecommerce/product/_search{ "size":0, "aggs": { "group_by_tags": { "terms": { "field": "tags", "order": { "avg_price": "desc" } }, "aggs": { "avg_price": { "avg": { "field": "price" } } } } }}按照指定的价格范围区间进行分组，然后在每组内再安装tag进行分组，最后在计算每组的平均价格
GET /ecommerce/product/_search{ "size":0, "aggs": { "group_by_price": { "range": { "field": "price", "ranges": [{ "from": "0", "to":20 }, { "from": "20", "to":40 }, { "from": "40", "to":60 } ] }, "aggs": { "group_by_tags": { "terms": { "field": "tags" }, "aggs": { "avg_price": { "avg": { "field": "price" } } } } } } }}电商网站商品管理(一)
原文地址：http://blog.51cto.com/395469372/2113385