03 搜索api

准备数据

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": "youxiao 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"
  ]
}

1、query string search

示例1

搜索全部商品：GET /ecommerce/product/_search

查询：

GET /ecommerce/product/_search

结果：

{
  "took": 3,  // took：耗费了几毫秒
  "timed_out": false,  // timed_out：是否查询超时
  "_shards": {  // _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）
    "total": 5,
    "successful": 5,
    "failed": 0
  },
  "hits": {
    "total": 3, // hits.totalh：查询结果的数量，3个document
    "max_score": 1,  //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.hits：包含了匹配搜索的document的详细数据
      {
        "_index": "ecommerce",
        "_type": "product",
        "_id": "2",
        "_score": 1,
        "_source": {
          "name": "jiajieshi yagao",
          "desc": "youxiao fangzhu",
          "price": 25,
          "producer": "jiajieshi producer",
          "tags": [
            "fangzhu"
          ]
        }
      },
      {
        "_index": "ecommerce",
        "_type": "product",
        "_id": "1",
        "_score": 1,
        "_source": {
          "name": "gaolujie yagao",
          "desc": "gaoxiao meibai",
          "price": 30,
          "producer": "gaolujie producer",
          "tags": [
            "meibai",
            "fangzhu"
          ]
        }
      },
      {
        "_index": "ecommerce",
        "_type": "product",
        "_id": "3",
        "_score": 1,
        "_source": {
          "name": "zhonghua yagao",
          "desc": "caoben zhiwu",
          "price": 40,
          "producer": "zhonghua producer",
          "tags": [
            "qingxin"
          ]
        }
      }
    ]
  }
}

示例2

搜索商品名称中包含yagao的商品，而且按照售价降序排序：

GET /ecommerce/product/_search?q=name:yagao&sort=price:desc

{
  "took": 42,
  "timed_out": false,
  "_shards": {
    "total": 5,
    "successful": 5,
    "failed": 0
  },
  "hits": {
    "total": 3,
    "max_score": null,
    "hits": [
      {
        "_index": "ecommerce",
        "_type": "product",
        "_id": "3",
        "_score": null,
        "_source": {
          "name": "zhonghua yagao",
          "desc": "caoben zhiwu",
          "price": 40,
          "producer": "zhonghua producer",
          "tags": [
            "qingxin"
          ]
        },
        "sort": [
          40
        ]
      },
      {
        "_index": "ecommerce",
        "_type": "product",
        "_id": "1",
        "_score": null,
        "_source": {
          "name": "gaolujie yagao",
          "desc": "gaoxiao meibai",
          "price": 30,
          "producer": "gaolujie producer",
          "tags": [
            "meibai",
            "fangzhu"
          ]
        },
        "sort": [
          30
        ]
      },
      {
        "_index": "ecommerce",
        "_type": "product",
        "_id": "2",
        "_score": null,
        "_source": {
          "name": "jiajieshi yagao",
          "desc": "youxiao fangzhu",
          "price": 25,
          "producer": "jiajieshi producer",
          "tags": [
            "fangzhu"
          ]
        },
        "sort": [
          25
        ]
      }
    ]
  }
}

query string search的由来，因为search参数都是以http请求的query string来附带的。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；但是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。

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，比query string search肯定强大多了。

示例1：query

查询所有的商品

GET ecommerce/product/_search
{
  "query":{  // 定义查询条件
    "match_all": {}
  }
}

示例2：sort

查询名称包含yagao的商品，同时按照价格降序排序

格式:

GET ecommerce/product/_search
{
  "query": {
    "match": {
      "FIELD": "TEXT"
    }
  },
  "sort": [
    {
      "FIELD": {
        "order": "desc"
      }
    }
  ]
}

示例：

GET ecommerce/product/_search
{
  "query": { // 定义查询条件
    "match": { // 条件类型
      "name": "yagao"
    }
  },
  "sort": [ // 定义排序条件
    {
      "price": { // 排序字段
        "order": "desc"
      }
    }
  ]
}

或：
GET ecommerce/product/_search
{
  "query": {
    "match": {
      "name": "yagao"
    }
  },
  "sort": [
    {
      "price":  "desc"
    }
  ]
}

示例3：from-size（分页）

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": {
      "name": "yagao"
    }
  },
  "sort": [
    {
      "price": "desc"
    }
  ],
  "from": 1,  //目标数据的偏移值，默认from为0
  "size": 1		// 当前返回的数据数目，默认size为10
}

示例4：_source（投影查询）

指定要查询出来商品的名称和价格就可以（投影操作），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": {
      "name": "yagao"
    }
  },
  "_source": [  // 指定_source字段的要显示的字段
    "name",
    "price"
  ]
}

结果：

{
  "took": 36,
  "timed_out": false,
  "_shards": {
    "total": 5,
    "successful": 5,
    "failed": 0
  },
  "hits": {
    "total": 3,
    "max_score": 0.25811607,
    "hits": [
      {
        "_index": "ecommerce",
        "_type": "product",
        "_id": "2",
        "_score": 0.25811607,
        "_source": {
          "price": 25,
          "name": "jiajieshi yagao"
        }
      },
      {
        "_index": "ecommerce",
        "_type": "product",
        "_id": "1",
        "_score": 0.25811607,
        "_source": {
          "price": 30,
          "name": "gaolujie yagao"
        }
      },
      {
        "_index": "ecommerce",
        "_type": "product",
        "_id": "3",
        "_score": 0.25811607,
        "_source": {
          "price": 40,
          "name": "zhonghua yagao"
        }
      }
    ]
  }
}

bool查询

bool：布尔值查询

must：且操作。一个must下可以有多个match，必须同时满足
must_not：非操作。多个条件，都不满足
should：或操作。至少一个满足
filter：过滤操作。子句查询。

以上3种操作的操作对象是match匹配

GET /ecommerce/product/_search
{
  "query": {
    "bool": {
      "must": [
        {
          "match": {
            "name": "yagao"
          }
        },
        {
          "match": {
            "price": "40"
          }
        }
      ]
    }
  }
}

3、query filter

一个查询语句究竟具有什么样的行为和得到什么结果，主要取决于它到底是处Query还是Filter。两者有很大区别：

Query context 查询上下文 这种语句在执行时既要计算文档是否匹配，还要计算文档相对于其他文档的匹配度有多高，匹配度越高，_score 分数就越高

Filter context 过滤上下文 过滤上下文中的语句在执行时只关心文档是否和查询匹配，不会计算匹配度，也就是得分。

示例1：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": {
            "gte": 25
          }
        }
      }
    }
  }
}

4、full-text search（全文检索）

示例1：分析全文解锁的过程

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：

分词	doc_id
special	4
yagao	4
producer	1,2,3,4
gaolujie	1
zhognhua	3
jiajieshi	2

搜索字符串也会被分词：yagao producer —> yagao和producer

所以producer字段包含yagao或producer都会被检索到。

结果：

{
  "took": 4,
  "timed_out": false,
  "_shards": {
    "total": 5,
    "successful": 5,
    "failed": 0
  },
  "hits": {
    "total": 3,
    "max_score": 0.25811607,
    "hits": [
      {
        "_index": "ecommerce",
        "_type": "product",
        "_id": "2",
        "_score": 0.25811607,
        "_source": {
          "name": "jiajieshi yagao",
          "desc": "youxiao fangzhu",
          "price": 25,
          "producer": "jiajieshi producer",
          "tags": [
            "fangzhu"
          ]
        }
      },
      {
        "_index": "ecommerce",
        "_type": "product",
        "_id": "1",
        "_score": 0.25811607,
        "_source": {
          "name": "gaolujie yagao",
          "desc": "gaoxiao meibai",
          "price": 30,
          "producer": "gaolujie producer",
          "tags": [
            "meibai",
            "fangzhu"
          ]
        }
      },
      {
        "_index": "ecommerce",
        "_type": "product",
        "_id": "3",
        "_score": 0.25811607,
        "_source": {
          "name": "zhonghua yagao",
          "desc": "caoben zhiwu",
          "price": 40,
          "producer": "zhonghua producer",
          "tags": [
            "qingxin"
          ]
        }
      }
    ]
  }
}

5、phrase search（短语搜索）

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；跟全文检索相反，phrase search，要求输入的搜索串是一个不可分割的整体，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。

// 插入一条临时数据
PUT /ecommerce/product/4
{
  "name": "special yagao",
  "desc": "special meibai",
  "price": 50,
  "producer": "special yagao producer",
  "tags": [
    "meibai"
  ]
}

示例：

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

结果：

{
  "took": 22,
  "timed_out": false,
  "_shards": {
    "total": 5,
    "successful": 5,
    "failed": 0
  },
  "hits": {
    "total": 1,
    "max_score": 0.70293105,
    "hits": [
      {
        "_index": "ecommerce",
        "_type": "product",
        "_id": "4",
        "_score": 0.70293105,
        "_source": {
          "name": "special yagao",
          "desc": "special meibai",
          "price": 50,
          "producer": "special yagao producer",
          "tags": [
            "meibai"
          ]
        }
      }
    ]
  }
}

term精确查询

term查询是直接通过倒排索引指定的词条进程精确查找的!

示例1

GET /ecommerce/product/_search
{
  "query": {
    "term": {
      "name": "yagao"
    }
  }
}

结果：

{
  "took": 3,
  "timed_out": false,
  "_shards": {
    "total": 5,
    "successful": 5,
    "failed": 0
  },
  "hits": {
    "total": 4,
    "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"
          ]
        }
      },
      {
        "_index": "ecommerce",
        "_type": "product",
        "_id": "3",
        "_score": 0.25811607,
        "_source": {
          "name": "zhonghua yagao",
          "desc": "caoben zhiwu",
          "price": 40,
          "producer": "zhonghua producer",
          "tags": [
            "qingxin"
          ]
        }
      },
      {
        "_index": "ecommerce",
        "_type": "product",
        "_id": "2",
        "_score": 0.16358379,
        "_source": {
          "name": "jiajieshi yagao",
          "desc": "youxiao fangzhu",
          "price": 25,
          "producer": "jiajieshi producer",
          "tags": [
            "fangzhu"
          ]
        }
      },
      {
        "_index": "ecommerce",
        "_type": "product",
        "_id": "4",
        "_score": 0.16358379,
        "_source": {
          "name": "special yagao",
          "desc": "special meibai",
          "price": 50,
          "producer": "special yagao producer",
          "tags": [
            "meibai"
          ]
        }
      }
    ]
  }
}

示例2

GET /ecommerce/product/_search
{
  "query": {
    "term": {
      "name": "gaolujie yagao"
    }
  }
}

结果：

{
  "took": 1,
  "timed_out": false,
  "_shards": {
    "total": 5,
    "successful": 5,
    "failed": 0
  },
  "hits": {
    "total": 0,
    "max_score": null,
    "hits": []
  }
}

发现没有结果，因为“gaolujie yagao”不是一个分词，不会存在倒排索引中。这种情况可以使用match_phrase查询。

6、highlight search（高亮搜索结果）

示例

GET /ecommerce/product/_search
{
  "query": {
    "match": {
      "producer": "producer"
    }
  },
  "highlight": {
    "fields": {
      "producer":{} //此处值任意
    }
  },
  "size": 1  //只显示1条记录
}

{
  "took": 7,
  "timed_out": false,
  "_shards": {
    "total": 5,
    "successful": 5,
    "failed": 0
  },
  "hits": {
    "total": 4,
    "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 <em>producer</em>" //被添加了html标签
          ]
        }
      }
    ]
  }
}

总结

query

match 匹配查询
bool：布尔值查询
- must：且操作。一个must下可以有多个match，必须同时满足
- must_not：非操作。
- should：或操作。
- filter