ES:多种搜索方式

1、query string search
搜索全部：

GET /ecommerce/product/_search

{
  "took": 2,
  "timed_out": false,
  "_shards": {
    "total": 5,
    "successful": 5,
    "failed": 0
  },
  "hits": {
    "total": 1,
    "max_score": 1,
    "hits": [
      {
        "_index": "ecommerce",
        "_type": "product",
        "_id": "1",
        "_score": 1,
        "_source": {
          "name": "gaolujie yagao",
          "desc": "gaoxiao meibai",
          "price": 30,
          "producer": "gaolujie producer",
          "tags": [
            "meibai",
            "fangzhu"
          ]
        }
      }
    ]
  }
}

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，1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

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
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
}

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"]
}

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 } 
                }
            }
        }
    }
}

4、full-text search（全文检索）

GET /ecommerce/product/_search
{
    "query" : {
        "match" : {
            "producer" : "yagao producer"
        }
    }
}

{
  "took": 56,
  "timed_out": false,
  "_shards": {
    "total": 5,
    "successful": 5,
    "failed": 0
  },
  "hits": {
    "total": 1,
    "max_score": 0.25811607,
    "hits": [
      {
        "_index": "ecommerce",
        "_type": "product",
        "_id": "1",
        "_score": 0.25811607,
        "_source": {
          "name": "gaolujie yagao",
          "desc": "gaoxiao meibai",
          "price": 30,
          "producer": "gaolujie producer",
          "tags": [
            "meibai",
            "fangzhu"
          ]
        }
      }
    ]
  }
}

producer这个字段，会先被拆解，建立倒排索引

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"
        }
    }
}

6、highlight search（高亮搜索结果）

GET /ecommerce/product/_search
{
    "query" : {
        "match" : {
            "producer" : "producer"
        }
    },
    "highlight": {
        "fields" : {
            "producer" : {}
        }
    }
}

{
  "took": 225,
  "timed_out": false,
  "_shards": {
    "total": 5,
    "successful": 5,
    "failed": 0
  },
  "hits": {
    "total": 1,
    "max_score": 0.25811607,
    "hits": [
      {
        "_index": "ecommerce",
        "_type": "product",
        "_id": "1",
        "_score": 0.25811607,
        "_source": {
          "name": "gaolujie yagao",
          "desc": "gaoxiao meibai",
          "price": 30,
          "producer": "gaolujie producer",
          "tags": [
            "meibai",
            "fangzhu"
          ]
        },
        "highlight": {
          "producer": [
            "gaolujie producer"
          ]
        }
      }
    ]
  }
}