面向文档
document数据格式
- 应用系统的数据结构都是面向对象的,复杂的
- 对象数据存储到数据库中,只能拆解开来,变为扁平的多张表,每次查询的时候还得还原回对象格式,相当麻烦
- ES是面向文档的,文档中存储的数据结构,与面向对象的数据结构是一样的,基于这种文档数据结构,es可以提供复杂的索引,全文检索,分析聚合等功能
- es的document用json数据格式来表达
Java数据
public class Employee {
private String email;
private String firstName;
private String lastName;
private EmployeeInfo info;
private Date joinDate;
}
private class EmployeeInfo {
private String bio; // 性格
private Integer age;
private String[] interests; // 兴趣爱好
}
EmployeeInfo info = new EmployeeInfo();
info.setBio("curious and modest");
info.setAge(30);
info.setInterests(new String[]{"bike", "climb"});
Employee employee = new Employee();
employee.setEmail("[email protected]");
employee.setFirstName("san");
employee.setLastName("zhang");
employee.setInfo(info);
employee.setJoinDate(new Date());
数据库数据
employee
id email first_name last_name join_date
001 [email protected] san zhang 2017/01/01
employee_info
employee_id bio age interests
001 curious and modest 30 bike, climb
Json数据
{
"email": "[email protected]",
"first_name": "san",
"last_name": "zhang",
"info": {
"bio": "curious and modest",
"age": 30,
"interests": [ "bike", "climb" ]
},
"join_date": "2017/01/01"
}
集群管理
GET /_cat/health?v
green:每个索引的primary shard和replica shard都是active状态的
yellow:每个索引的primary shard都是active状态的,但是部分replica shard不是active状态,处于不可用的状态
red:不是所有索引的primary shard都是active状态的,部分索引有数据丢失了
现在只启动动了一个es进程,相当于就只有一个node。现在es中有一个index,就是kibana自己内置建立的index。由于默认的配置是给每个index分配5个primary shard和5个replica shard,而且primary shard和replica shard不能在同一台机器上(为了容错)。现在kibana自己建立的index是1个primary shard和1个replica shard。当前就一个node,所以只有1个primary shard被分配了和启动了,但是一个replica shard没有第二台机器去启动。只要启动第二个es进程,就会在es集群中有2个node,然后那1个replica shard就会自动分配过去,然后cluster status就会变成green状态。
新增
#语法
PUT /index/type/id
{
"json数据"
}
# 添加商品1
PUT /ecommerce/product/1
{
"name" : "gaolujie yagao", #商品名称
"desc" : "gaoxiao meibai", #商品描述
"price" : 30, #商品价格
"producer" : "gaolujie producer", #生厂厂家
"tags": [ "meibai", "fangzhu" ] #产品标签
}
#添加商品2
PUT /ecommerce/product/2
{
"name" : "jiajieshi yagao",
"desc" : "youxiao fangzhu",
"price" : 25,
"producer" : "jiajieshi producer",
"tags": [ "fangzhu" ]
}
#添加商品3
PUT /ecommerce/product/3
{
"name" : "zhonghua yagao",
"desc" : "caoben zhiwu",
"price" : 40,
"producer" : "zhonghua producer",
"tags": [ "qingxin" ]
}
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
查询
#语法
GET /index/type/id
GET /ecommerce/product/1
{
"_index": "ecommerce",
"_type": "product",
"_id": "1",
"_version": 1,
"found": true,
"_source": {
"name": "gaolujie yagao",
"desc": "gaoxiao meibai",
"price": 30,
"producer": "gaolujie producer",
"tags": [
"meibai",
"fangzhu"
]
}
}
修改
PUT /ecommerce/product/1
{
"name" : "jiaqiangban gaolujie yagao",
"desc" : "gaoxiao meibai",
"price" : 30,
"producer" : "gaolujie producer",
"tags": [ "meibai", "fangzhu" ]
}
删除
DELETE /ecommerce/product/1
查询
query string search
query string search的由来:因为search参数都是以http请求的query string来附带的
{
"took": 3,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"failed": 0
},
"hits": {
"total": 3,
"max_score": 1,
"hits":
......
{
"_index": "ecommerce",
"_type": "product",
"_id": "3",
"_score": 1,
"_source": {
"name": "zhonghua yagao",
"desc": "caoben zhiwu",
"price": 40,
"producer": "zhonghua producer",
"tags": [
"qingxin"
]
......
}
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)
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
按售价降序排列
GET /ecommerce/product/_search?q=name:yagao&sort=price:desc
适用场景
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;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
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
GET /ecommerce/product/_search
{
"query": { "match_all": {} }
}
条件查询
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
}
指定查询
更加适合生产环境的使用,可以构建复杂的查询
GET /ecommerce/product/_search
{
"query": { "match_all": {} },
"_source": ["name", "price"]
}
query filter
过滤查询
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 }
}
}
}
}
}
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 会被拆解为 yagao和producer
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"
}
}
}
highlight search(高亮搜索结果)
GET /ecommerce/product/_search
{
"query" : {
"match" : {
"producer" : "producer"
}
},
"highlight": {
"fields" : {
"producer" : {}
}
}
}