elasticsearch的3个基本问题之读取数据
如何从ES读取数据，包括两种方式，直接获取和通过搜索获取
1. 直接获取
GET index/type/ID的方式可以直接获取到某个index下的某个type的，文档ID是ID的doc。e.g.
curl -XGET http://10.19.26.43:9200/nats-log-2016-04-20/logs/AVQvYyK6aK8LxcWQ324f
and the return
{"_index":"nats-log-2016-04-20”,"_type":"logs","_id":"AVQvYyK6aK8LxcWQ324f”,
"_version":1,"found":true,
"_source”:{xxx}
}
2. 通过search获取数据
(1) 简单的字段匹配搜索
GET /megacorp/employee/_search?q=last_name:Smith
e.g.
curl -XGET http://10.19.26.43:9200/nats-log-2016-04-20/logs/_search?q=HostName:search-extng1-cnc0.hlg01
{"took":7450,"timed_out":false,"_shards":{"total":5,"successful":5,"failed":0},"hits”:{xxx}}
curl -XGET http://10.19.26.43:9200/nats-log-2016-04-20/logs/_search?q=search-extng1-cnc0.hlg01
{"took":9114,"timed_out":false,"_shards":{"total":5,"successful":5,"failed":0},"hits":{"total":172019921,"max_score":0.8222273,"hits”:xx}}
（2）单字段的精准匹配
GET /megacorp/employee/_search?q=last_name:"Smith"
（3）使用DSL进行复杂的搜索
1) 字段匹配
GET /index/type/_search
{
"query" : {
"filtered" : {
"filter" : {
"range" : {
"age" : { "gt" : 30 } <1>
}
},
"query" : {
"match" : {
"last_name" : "Smith" <2>
}
}
}
}
}
2）段落匹配
GET /megacorp/employee/_search
{
"query" : {
"match_phrase" : {
"about" : "rock climbing"
}
}
}
3）高亮匹配的关键词
GET /megacorp/employee/_search
{
"query" : {
"match_phrase" : {
"about" : "rock climbing"
}
},
"highlight": {
"fields" : {
"about" : {}
}
}
}
当我们运行这个查询后，相同的命中结果会被返回，但是我们会得到一个新的名叫 highlight 的部分。在这里包含了 about 字段中的匹配单词，并且会被 <em></em> HTML字符包裹住：
{
...
"hits": {
"total": 1,
"max_score": 0.23013961,
"hits": [
{
...
"_score": 0.23013961,
"_source": {
"first_name": "John",
"last_name": "Smith",
"age": 25,
"about": "I love to go rock climbing",
"interests": [ "sports", "music" ]
},
"highlight": {
"about": [
"I love to go <em>rock</em> <em>climbing</em>" <1>
]
}
}
]
}
}