Elasticsearch--多种搜索方式

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quey string search

搜索全部：

    GET /index/type/_search

示例：

    GET /ecommerce/product/_search

返回：

    {
      "took": 2,
      "timed_out": false,
      "_shards": {//分片，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,
        "skipped": 0,
        "failed": 0
      },
      "hits": {
        "total": 2,//查询结果的数量
        "max_score": 1,//document对于一个search的相关度的匹配分数，约相关，就越匹配，分数越高
        "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": "3",
            "_score": 1,
            "_source": {
              "name": "zhonghua yagao",
              "desc": "caoben zhiwu",
              "price": 40,
              "producer": "zhonghua producer",
              "tags": [
                "qingxin"
              ]
            }
          }
        ]
      }
    }

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

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

返回：

    {
      "took": 16,
      "timed_out": false,
      "_shards": {
        "total": 5,
        "successful": 5,
        "skipped": 0,
        "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
            ]
          }
        ]
      }
    }

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

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：查询所有商品

    GET /ecommerce/product/_search
    {
      "query": { "match_all": {} }
    }

返回结果同上

示例：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" }
        ]
    }

示例：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
    }

返回：

    {
      "took": 0,
      "timed_out": false,
      "_shards": {
        "total": 5,
        "successful": 5,
        "skipped": 0,
        "failed": 0
      },
      "hits": {
        "total": 3,
        "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"
              ]
            }
          }
        ]
      }
    }

示例：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"]
    }

返回：

    {
      "took": 7,
      "timed_out": false,
      "_shards": {
        "total": 5,
        "successful": 5,
        "skipped": 0,
        "failed": 0
      },
      "hits": {
        "total": 3,
        "max_score": 1,
        "hits": [
          {
            "_index": "ecommerce",
            "_type": "product",
            "_id": "2",
            "_score": 1,
            "_source": {
              "price": 25,
              "name": "jiajieshi yagao"
            }
          },
          {
            "_index": "ecommerce",
            "_type": "product",
            "_id": "1",
            "_score": 1,
            "_source": {
              "price": 30,
              "name": "gaolujie yagao"
            }
          },
          {
            "_index": "ecommerce",
            "_type": "product",
            "_id": "3",
            "_score": 1,
            "_source": {
              "price": 40,
              "name": "zhonghua yagao"
            }
          }
        ]
      }
    }

query filter

示例：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 } 
                    }
                }
            }
        }
    }

返回：

    {
      "took": 0,
      "timed_out": false,
      "_shards": {
        "total": 5,
        "successful": 5,
        "skipped": 0,
        "failed": 0
      },
      "hits": {
        "total": 2,
        "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"
              ]
            }
          }
        ]
      }
    }

full-text search（全文检索）

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

返回：

    {
      "took": 2,
      "timed_out": false,
      "_shards": {
        "total": 5,
        "successful": 5,
        "skipped": 0,
        "failed": 0
      },
      "hits": {
        "total": 4,
        "max_score": 0.70293105,
        "hits": [
          {
            "_index": "ecommerce",
            "_type": "product",
            "_id": "4",
            "_score": 0.70293105,//包含 "yagao"和"producer"两个词语，匹配度最高
            "_source": {
              "name": "special yagao",
              "desc": "special meibai",
              "price": 50,
              "producer": "special yagao producer",
              "tags": [
                "meibai"
              ]
            }
          },
          {
            "_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": 0.1805489,
            "_source": {
              "name": "jiajieshi yagao",
              "desc": "youxiao fangzhu",
              "price": 25,
              "producer": "jiajieshi producer",
              "tags": [
                "fangzhu"
              ]
            }
          }
        ]
      }
    }

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"
            }
        }
    }

返回：

    {
      "took": 5,
      "timed_out": false,
      "_shards": {
        "total": 5,
        "successful": 5,
        "skipped": 0,
        "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"
              ]
            }
          }
        ]
      }
    }

highlight search（高亮搜索结果）

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