ElasticSearch索引数据

古城微笑少年丶 2022-10-30 12:21 15阅读 0赞

## 一、Query String Search(‘Query String’方式的搜索) ##

1.搜索全部商品

GET /shop_index/productInfo/_search

返回结果：

{
      "took": 8,
      "timed_out": false,
      "_shards": {
        "total": 5,
        "successful": 5,
        "skipped": 0,
        "failed": 0
      },
      "hits": {
        "total": 3,
        "max_score": 1,
        "hits": [
          {
            "_index": "shop_index",
            "_type": "productInfo",
            "_id": "2",
            "_score": 1,
            "_source": {
              "test": "test"
            }
          },
          {
            "_index": "shop_index",
            "_type": "productInfo",
            "_id": "zyWpRGkB8mgaHjxk0Hfo",
            "_score": 1,
            "_source": {
              "name": "HuaWei P20",
              "desc": "Expen but easy to use",
              "price": 5300,
              "producer": "HuaWei Producer",
              "tags": [
                "Expen",
                "Fast"
              ]
            }
          },
          {
            "_index": "shop_index",
            "_type": "productInfo",
            "_id": "1",
            "_score": 1,
            "_source": {
              "name": "HuaWei Mate8",
              "desc": "Cheap and easy to use",
              "price": 2500,
              "producer": "HuaWei Producer",
              "tags": [
                "Cheap",
                "Fast"
              ]
            }
          }
        ]
      }
    }

字段解释：

took:耗费了几毫秒
    timed_out:是否超时，这里是没有
    _shards:数据被拆到了5个分片上，搜索时使用了5个分片，5个分片都成功地返回了数据，失败了0个，跳过了0个
    hits.total:查询结果的数量，3个document
    max_score:就是document对于一个search的相关度的匹配分数，越相关，就越匹配，分数也越高
    hits.hits:包含了匹配搜索的document的详细数据

2.搜索商品名称中包含HuaWei的商品，而且按照售价降序排序：  
下面这种方法也是"Query String Search"的由来，因为search参数都是以http请求的query string来附带的.

GET /shop_index/productInfo/_search?q=name:HuaWei&sort=price:desc

返回结果：

{
      "took": 23,
      "timed_out": false,
      "_shards": {
        "total": 5,
        "successful": 5,
        "skipped": 0,
        "failed": 0
      },
      "hits": {
        "total": 2,
        "max_score": null,
        "hits": [
          {
            "_index": "shop_index",
            "_type": "productInfo",
            "_id": "zyWpRGkB8mgaHjxk0Hfo",
            "_score": null,
            "_source": {
              "name": "HuaWei P20",
              "desc": "Expen but easy to use",
              "price": 5300,
              "producer": "HuaWei Producer",
              "tags": [
                "Expen",
                "Fast"
              ]
            },
            "sort": [
              5300
            ]
          },
          {
            "_index": "shop_index",
            "_type": "productInfo",
            "_id": "1",
            "_score": null,
            "_source": {
              "name": "HuaWei Mate8",
              "desc": "Cheap and easy to use",
              "price": 2500,
              "producer": "HuaWei Producer",
              "tags": [
                "Cheap",
                "Fast"
              ]
            },
            "sort": [
              2500
            ]
          }
        ]
      }
    }

## 二、Query DSL(DSL: Domain Specified Language，特定领域的语言) ##

这种方法是通过一个json格式的http request body请求体作为条件，可以完成多种复杂的查询需求，比query string的功能更加强大  
1.搜索所有商品

GET /shop_index/productInfo/_search
    {
      "query": {
        "match_all": {}
      }
    }

返回结果省略...

2.查询名称中包含HuaWei的商品，并且按照价格降序排列

GET /shop_index/productInfo/_search
    {
      "query": {
        "match": {
          "name": "HuaWei"
        }
      },
      "sort": [
        {
          "price": {
            "order": "desc"
          }
        }
      ]
    }

返回结果省略...

3.分页查询第二页，每页1条记录

GET /shop_index/productInfo/_search
    {
      "query": {
        "match_all": {}
      },
      "from": 1,
      "size": 1
    }

返回结果：

{
      "took": 6,
      "timed_out": false,
      "_shards": {
        "total": 5,
        "successful": 5,
        "skipped": 0,
        "failed": 0
      },
      "hits": {
        "total": 3,
        "max_score": 1,
        "hits": [
          {
            "_index": "shop_index",
            "_type": "productInfo",
            "_id": "zyWpRGkB8mgaHjxk0Hfo",
            "_score": 1,
            "_source": {
              "name": "HuaWei P20",
              "desc": "Expen but easy to use",
              "price": 5300,
              "producer": "HuaWei Producer",
              "tags": [
                "Expen",
                "Fast"
              ]
            }
          }
        ]
      }
    }

注意：  
(1)在实际项目中，如果有条件查询之后再需要分页，不需要单独查询总条数，ES会返回满足条件的总条数，可以直接使用；  
(2)ES的分页默认from是从0开始的；

4.只查询特定字段，比如：name，desc和price字段，其他字段不需要返回

GET /shop_index/productInfo/_search
    {
      "query": {
        "match": {
          "name": "HuaWei"
        }
      },
      "_source": ["name","desc","price"]
    }

返回结果：

{
      "took": 27,
      "timed_out": false,
      "_shards": {
        "total": 5,
        "successful": 5,
        "skipped": 0,
        "failed": 0
      },
      "hits": {
        "total": 2,
        "max_score": 0.2876821,
        "hits": [
          {
            "_index": "shop_index",
            "_type": "productInfo",
            "_id": "zyWpRGkB8mgaHjxk0Hfo",
            "_score": 0.2876821,
            "_source": {
              "price": 5300,
              "name": "HuaWei P20",
              "desc": "Expen but easy to use"
            }
          },
          {
            "_index": "shop_index",
            "_type": "productInfo",
            "_id": "1",
            "_score": 0.2876821,
            "_source": {
              "price": 2500,
              "name": "HuaWei Mate8",
              "desc": "Cheap and easy to use"
            }
          }
        ]
      }
    }

## 三.Query Filter(对查询结果进行过滤) ##

比如：查询名称中包含HuaWei，并且价格大于4000的商品记录:

GET /shop_index/productInfo/_search
    {
      "query": {
        "bool": {
          "must": [
            {
              "match": {
                "name": "HuaWei"
              }
            }
          ], 
          "filter": {
            "range": {
              "price": {
                "gt": 4000
              }
            }
          }
        }
      }
    }

返回结果：

{
      "took": 195,
      "timed_out": false,
      "_shards": {
        "total": 5,
        "successful": 5,
        "skipped": 0,
        "failed": 0
      },
      "hits": {
        "total": 1,
        "max_score": 0.2876821,
        "hits": [
          {
            "_index": "shop_index",
            "_type": "productInfo",
            "_id": "zyWpRGkB8mgaHjxk0Hfo",
            "_score": 0.2876821,
            "_source": {
              "name": "HuaWei P20",
              "desc": "Expen but easy to use",
              "price": 5300,
              "producer": "HuaWei Producer",
              "tags": [
                "Expen",
                "Fast"
              ]
            }
          }
        ]
      }
    }

## 四、全文索引(Full-Text Search) ##

搜索生产厂商字段中包含"HuaWei MateProducer"的商品记录：

GET /shop_index/productInfo/_search
    {
      "query": {
        "match": {
          "producer": "HuaWei MateProducer"
        }
      }
    }

返回结果：

{
      "took": 8,
      "timed_out": false,
      "_shards": {
        "total": 5,
        "successful": 5,
        "skipped": 0,
        "failed": 0
      },
      "hits": {
        "total": 4,
        "max_score": 0.5753642,
        "hits": [
          {
            "_index": "shop_index",
            "_type": "productInfo",
            "_id": "SiUBRWkB8mgaHjxkJHyS",
            "_score": 0.5753642,
            "_source": {
              "name": "HuaWei Mate10",
              "desc": "Cheap and Beauti",
              "price": 2300,
              "producer": "HuaWei MateProducer",
              "tags": [
                "Cheap",
                "Beauti"
              ]
            }
          },
          {
            "_index": "shop_index",
            "_type": "productInfo",
            "_id": "1",
            "_score": 0.2876821,
            "_source": {
              "name": "HuaWei Mate8",
              "desc": "Cheap and easy to use",
              "price": 2500,
              "producer": "HuaWei Producer",
              "tags": [
                "Cheap",
                "Fast"
              ]
            }
          },
          {
            "_index": "shop_index",
            "_type": "productInfo",
            "_id": "zyWpRGkB8mgaHjxk0Hfo",
            "_score": 0.18232156,
            "_source": {
              "name": "HuaWei P20",
              "desc": "Expen but easy to use",
              "price": 5300,
              "producer": "HuaWei Producer",
              "tags": [
                "Expen",
                "Fast"
              ]
            }
          },
          {
            "_index": "shop_index",
            "_type": "productInfo",
            "_id": "CSX8RGkB8mgaHjxkV3w1",
            "_score": 0.18232156,
            "_source": {
              "name": "HuaWei nova 4e",
              "desc": "cheap and look nice",
              "price": 1999,
              "producer": "HuaWei Producer",
              "tags": [
                "Cheap",
                "Nice"
              ]
            }
          }
        ]
      }
    }

从以上结果中可以看到：  
id为"SiUBRWkB8mgaHjxkJHyS"的记录score分数最高，表示匹配度最高;  
原因：  
producer分完词之后包括的词语有：  
(1).HuaWei:  
匹配到改词的记录ID：'SiUBRWkB8mgaHjxkJHyS','1','CSX8RGkB8mgaHjxkV3w1','zyWpRGkB8mgaHjxk0Hfo'  
(2).MateProducer:  
匹配到该词的记录ID：'SiUBRWkB8mgaHjxkJHyS'  
由于"HuaWei MateProducer"两次匹配到ID为'SiUBRWkB8mgaHjxkJHyS'的记录，所以该记录的score分数最高。

## 五、Phrase Search(短语搜索) ##

短语索引和全文索引的区别：  
(1)全文匹配：将要搜索的内容分词，然后挨个单词去倒排索引中匹配，只要匹配到任意一个单词，就算是匹配到记录;  
(2)短语索引：输入的搜索串，必须在指定的字段内容中，完全包含一模一样的，才可以算匹配，才能作为结果返回;  
例如：搜索name中包含"HuaWei MateProducer"短语的商品信息:

GET /shop_index/productInfo/_search
    {
      "query": {
        "match_phrase": {
          "producer": "HuaWei MateProducer"
        }
      }
    }

返回结果：

{
      "took": 158,
      "timed_out": false,
      "_shards": {
        "total": 5,
        "successful": 5,
        "skipped": 0,
        "failed": 0
      },
      "hits": {
        "total": 1,
        "max_score": 0.5753642,
        "hits": [
          {
            "_index": "shop_index",
            "_type": "productInfo",
            "_id": "SiUBRWkB8mgaHjxkJHyS",
            "_score": 0.5753642,
            "_source": {
              "name": "HuaWei Mate10",
              "desc": "Cheap and Beauti",
              "price": 2300,
              "producer": "HuaWei MateProducer",
              "tags": [
                "Cheap",
                "Beauti"
              ]
            }
          }
        ]
      }
    }

可以看到只有包含"HuaWei MateProducer"的记录才被返回。

## 六、Highlight Search(搜索高亮显示) ##

高亮搜索指的是搜索的结果中，将某些特别需要强调的词使用特定的样式展示出来。  
例如：搜索商品名称中包含"Xiao'Mi"的商品，并将搜索的关键词高亮显示：

GET /shop_index/productInfo/_search
    {
      "query": {
        "match": {
          "name": "Xiao'Mi"
        }
      },
      "highlight": {
        "fields": {
          "name": {}
        }
      }
    }

返回结果：

{
 "took": 348,
 "timed_out": false,
 "_shards": {
 "total": 5,
 "successful": 5,
 "skipped": 0,
 "failed": 0
 },
 "hits": {
 "total": 1,
 "max_score": 0.2876821,
 "hits": [
 {
 "_index": "shop_index",
 "_type": "productInfo",
 "_id": "HiX9RGkB8mgaHjxk4nxC",
 "_score": 0.2876821,
 "_source": {
 "name": "Xiao'Mi 9",
 "desc": "Expen but nice and Beauti",
 "price": 3500,
 "producer": "XiaoMi Producer",
 "tags": [
 "Expen",
 "Beauti"
 ]
 },
 "highlight": {
 "name": [
 "Xiao'Mi 9"
 ]
 }
 }
 ]
 }
 }

可以看到，"Xiao'Mi"使用了标签返回了，可以在HTML中直接以斜体展示。  
如果想使用自定义高亮样式，可以使用pre\_tags和post\_tags进行自定义，比如：想使用红色展示，如下所示：

GET /shop_index/productInfo/_search
 {
 "query": {
 "match": {
 "name": "Xiao'Mi"
 }
 },
 "highlight": {
 "fields": {
 "name": {}
 },
 "pre_tags": [
 ""
 ],
 "post_tags": [
 ""
 ]
 }
 }

返回结果：

{
 "took": 10,
 "timed_out": false,
 "_shards": {
 "total": 5,
 "successful": 5,
 "skipped": 0,
 "failed": 0
 },
 "hits": {
 "total": 1,
 "max_score": 0.2876821,
 "hits": [
 {
 "_index": "shop_index",
 "_type": "productInfo",
 "_id": "HiX9RGkB8mgaHjxk4nxC",
 "_score": 0.2876821,
 "_source": {
 "name": "Xiao'Mi 9",
 "desc": "Expen but nice and Beauti",
 "price": 3500,
 "producer": "XiaoMi Producer",
 "tags": [
 "Expen",
 "Beauti"
 ]
 },
 "highlight": {
 "name": [
 "Xiao'Mi 9"
 ]
 }
 }
 ]
 }
 }

返回结果中的搜索关键字使用表示红色的css样式展示出来。

## 七、聚合索引 ##

聚合索引最主要是采用aggs关键字对具体field进行group by

GET /transaction/_search
    {
        "size": 2,
        "aggs": {
          "group_by_hostId": {
            "terms": { "field": "rewardInfo.hostId" },
            "aggs" : { 
              "sum_coins": { "sum": { "field": "rewardInfo.coins" }}
              }
        }
      },
        "query": {
        "match": {
          "userId": "6VbNp"
        }
      }
    }

执行结果：

{
      "took" : 1,
      "timed_out" : false,
      "_shards" : {
        "total" : 1,
        "successful" : 1,
        "skipped" : 0,
        "failed" : 0
      },
      "hits" : {
        "total" : {
          "value" : 0,
          "relation" : "eq"
        },
        "max_score" : null,
        "hits" : [ ]
      },
      "aggregations" : {
        "group_by_hostId" : {
          "doc_count_error_upper_bound" : 0,
          "sum_other_doc_count" : 0,
          "buckets" : [ ]
        }
      }
    }

## 六、求最大值、最小值、平均值、和 ##

主要是利用关键词max, min, avg, sum

GET /transaction/_search
    {
        "size": 2,
        "aggs": {
              "sum_coins": { "sum": { "field": "rewardInfo.coins" }}, 
              "max_coins": { "max": { "field": "rewardInfo.coins" }}, 
              "min_coins": { "min": { "field": "rewardInfo.coins" }},
              "avg_coins": { "avg": { "field": "rewardInfo.coins" }}
      },
        "query": {
        "match": {
          "userId": "6VbNp"
        }
      }
    }

执行结果：

{
      "took" : 43,
      "timed_out" : false,
      "_shards" : {
        "total" : 1,
        "successful" : 1,
        "skipped" : 0,
        "failed" : 0
      },
      "hits" : {
        "total" : {
          "value" : 0,
          "relation" : "eq"
        },
        "max_score" : null,
        "hits" : [ ]
      },
      "aggregations" : {
        "max_coins" : {
          "value" : null
        },
        "min_coins" : {
          "value" : null
        },
        "avg_coins" : {
          "value" : null
        },
        "sum_coins" : {
          "value" : 0.0
        }
      }
    }