6.Request Query 详解

1. Request Body Search

将查询语句通过HTTP Request Body 发送给Elasticsearch

1.1 404_idx

//ignore_unavailable=true，可以忽略尝试访问不存在的索引“404_idx”导致的报错
POST /test,404_idx/_search?ignore_unavailable=true
{
  "profile": true,
	"query": {
		"match_all": {}
	}
}
// 没有test 这个索引 但是并不会报错 而是返回hit number 为0
{
  "took" : 0,
  "timed_out" : false,
  "_shards" : {
    "total" : 0,
    "successful" : 0,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 0,
      "relation" : "eq"
    },
    "max_score" : 0.0,
    "hits" : [ ]
  }
}

1.2 分页

from表示从第10个开始显示
size表示一页显示20个
获取靠后的翻页成本较高

POST /kibana_sample_data_ecommerce/_search
{
  "from":10,
  "size":20,
  "query":{
    "match_all": {}
  }
}

1.3 排序

最好在“数字型”和"日期型"字段上排序
因为对于多值类型或分析过的字段排序，系统会选一个值，无法得知该值

// 以下按照order_date日期字段降序排序
POST kibana_sample_data_ecommerce/_search
{
  "sort":[{"order_date":"desc"}],
  "from": 10,
  "size": 5, 
  "query":{
    "match_all": {}
  }
}

1.4 _source filtering

如果_source 没有存储，那就只返回匹配的文档的元数据
_source 支持使用通配符

POST /kibana_sample_data_ecommerce/_search
{
  "_source": ["currency","customer_first_name"],
  "query": {"match_all": {}}
}
# 返回结果 可见 source 只有两个字段
"hits" : [
  {
    "_index" : "kibana_sample_data_ecommerce",
    "_type" : "_doc",
    "_id" : "IxbH4WsBSYM1C2oZjVdu",
    "_score" : 1.0,
    "_source" : {
      "customer_first_name" : "rania",
      "currency" : "EUR"
    }
  },

1.5 脚本字段

订单中有不同的汇率，需要结合汇率对订单价格进行排序

   GET kibana_sample_data_ecommerce/_search
{
  "script_fields": {
    "new_field": {
      "script": {
        "lang":"painless",  	// 指定脚本语言 painless
        "source":"doc['order_date'].value+'_hello'"
      }
    }
  },
  "query": {"match_all": {}}
}

1.6 使用查询表达式 Match

POST movies/_search
{
  "profile": "true", 
  "query": {
    "match": {
      "title":{
        "query": "last christmas"    // OR 的关系
      }
    }
  }
}
# 返回结果
 "query" : [
          {
            "type" : "BooleanQuery",
            "description" : "title:last title:christmas",

布尔操作

POST movies/_search
{
  "profile": "true", 
  "query": {
    "match": {
      "title":{
        "query": "last christmas", 
        "operator": "and"	//AND 的关系
      }
    }
  }
}
# 返回结果
"query" : [
          {
            "type" : "BooleanQuery",
            "description" : "+title:last +title:christmas",

短语操作 Match Phrase

 	POST movies/_search
{
  "profile": "true", 
  "query": {
    "match_phrase": {
      "title":{
        "query": "one love"
      }
    }
  }
}
# 输出结果
 "query" : [
          {
            "type" : "PhraseQuery",
            "description" : """title:"one love"""",

slop的使用

   POST movies/_search
{
  "profile": "true", 
  "query": {
    "match_phrase": {
      "title":{
        "query": "one love",
        "slop":1 			//slop 表示两个单词中间可以有几个词
      }
    }
  }
}
# 输出结果
"query" : [
          {
            "type" : "PhraseQuery",
            "description" : """title:"one love"~1""",

2.1 Query String

1.存入数据

PUT /users/_doc/1
{
  "name":"Ruan Yiming",
  "about":"java, golang, node, swift, elasticsearch"
}

PUT /users/_doc/2
{
  "name":"Li Yiming",
  "about":"Hadoop"
}

query_string 支持AND OR

POST users/_search
{
  "query": {
    "query_string": {
      "default_field": "name",
      "query": "Ruan AND Yiming"
    }
  }
}

POST users/_search
{
  "query": {
    "query_string": {
      "fields":["name","about"],
      "query": "(Ruan AND Yiming) OR (hadoop)"
    }
  }
}

Simple Query

Simple Query 不支持 and or not 会当做字符串处理可以使用
+替代 AND
|替代 OR
-替代NOT

//Simple Query 默认的operator是 Or
POST users/_search
{
  "query": {
    "simple_query_string": {
      "query": "Ruan -Yiming",	 //查找 有Ruan 并且无Yiming的文档
      "fields": ["name"],
      "default_operator": "AND"
    }
  }
}

POST users/_search
{
  "query": {
    "simple_query_string": {
      "query": "Ruan Yiming",
      "fields": ["name"],
      "default_operator": "AND"
    }
  }
}