Elasticsearch DSL 查询

太过爱你忘了你带给我的痛 2021-12-03 11:27 547阅读 0赞

DSL 是 Domain Specific Language（特定领域语言）的缩写。

Elasticsearch 提供了功能丰富且灵活的查询语言，即 DSL 查询。你可以用它构建出更加复杂、功能更加强大的查询语句。

先来一个简单的例子，比如，我们可以这样查询 first_name 字段包含 John 的用户。

  1. GET /alibaba/user/_search
  2. {
  3.     "query" : {
  4.         "match" : {
  5.             "first_name" : "John"
  6.         }
  7.     }
  8. }

它会返回和上一节中的查询字符串搜索相同的结果。只不过这里我们不再使用查询字符串作为请求参数，而是使用 JSON 格式的请求体。

bool 联合查询

逻辑与（AND）

下面，我们来进行一个稍微复杂点的查询。比如，查询姓氏包含 Smith 且年龄大于 30 岁的用户。

  1. GET /alibaba/user/_search
  2. {
  3.     "query" : {
  4.         "bool" : {
  5.             "filter" : {
  6.                 "range" : {
  7.                     "info.age" : { "gt" : 30 }
  8.                 }
  9.             },
  10.             "must" : [{
  11.                 "match" : {
  12.                     "last_name" : "smith"
  13.                 }
  14.             }]
  15.         }
  16.     }
  17. }

返回结果：

  1. {
  2.   "took": 4,
  3.   "timed_out": false,
  4.   "_shards": {
  5.     "total": 5,
  6.     "successful": 5,
  7.     "failed": 0
  8.   },
  9.   "hits": {
  10.     "total": 1,
  11.     "max_score": 0.2876821,
  12.     "hits": [
  13.       {
  14.         "_index": "alibaba",
  15.         "_type": "user",
  16.         "_id": "3",
  17.         "_score": 0.2876821,
  18.         "_source": {
  19.           "email": "john3@smith.com",
  20.           "first_name": "John3",
  21.           "last_name": "Smith",
  22.           "full_name": "John3 Smith",
  23.           "info": {
  24.             "age": 35,
  25.             "interests": [
  26.               "sports",
  27.               "musics"
  28.             ],
  29.             "address": "guangdong shenzhen longhua"
  30.           },
  31.           "created_at": "2019-06-08 09:40:10"
  32.         }
  33.       }
  34.     ]
  35.   }
  36. }

查询 last_name 包含 Smith，且 full_name 包含 John 的用户。

  1. GET /alibaba/user/_search
  2. {
  3.   "query": {
  4.     "bool": {
  5.       "must": [
  6.         { "match": { "last_name": "Smith" } },
  7.         { "match": { "full_name": "John" } }
  8.       ]
  9.     }
  10.   }
  11. }

返回结果：

  1. {
  2.   "took": 4,
  3.   "timed_out": false,
  4.   "_shards": {
  5.     "total": 5,
  6.     "successful": 5,
  7.     "failed": 0
  8.   },
  9.   "hits": {
  10.     "total": 1,
  11.     "max_score": 0.5457982,
  12.     "hits": [
  13.       {
  14.         "_index": "alibaba",
  15.         "_type": "user",
  16.         "_id": "1",
  17.         "_score": 0.5457982,
  18.         "_source": {
  19.           "email": "john@smith.com",
  20.           "first_name": "John",
  21.           "last_name": "Smith",
  22.           "full_name": "John Smith",
  23.           "info": {
  24.             "age": 25,
  25.             "interests": [
  26.               "games",
  27.               "musics"
  28.             ],
  29.             "address": "guangdong shenzhen nanshan"
  30.           },
  31.           "created_at": "2019-06-06 08:30:10"
  32.         }
  33.       }
  34.     ]
  35.   }
  36. }

逻辑或（OR）

查询 info.age 大于 30 或 info.address 包含 baoan 的用户。

  1. GET /alibaba/user/_search
  2. {
  3.     "query": {
  4.         "bool": {
  5.             "should": [{
  6.                     "range": {
  7.                         "info.age": {
  8.                             "gt": 30
  9.                         }
  10.                     }
  11.                 },
  12.                 {
  13.                     "match": {
  14.                         "info.address": "baoan"
  15.                     }
  16.                 }
  17.             ]
  18.         }
  19.     }
  20. }

返回结果：

  1. {
  2.   "took": 8,
  3.   "timed_out": false,
  4.   "_shards": {
  5.     "total": 5,
  6.     "successful": 5,
  7.     "failed": 0
  8.   },
  9.   "hits": {
  10.     "total": 2,
  11.     "max_score": 1,
  12.     "hits": [
  13.       {
  14.         "_index": "alibaba",
  15.         "_type": "user",
  16.         "_id": "3",
  17.         "_score": 1,
  18.         "_source": {
  19.           "email": "john3@smith.com",
  20.           "first_name": "John3",
  21.           "last_name": "Smith",
  22.           "full_name": "John3 Smith",
  23.           "info": {
  24.             "age": 35,
  25.             "interests": [
  26.               "sports",
  27.               "musics"
  28.             ],
  29.             "address": "guangdong shenzhen longhua"
  30.           },
  31.           "created_at": "2019-06-08 09:40:10"
  32.         }
  33.       },
  34.       {
  35.         "_index": "alibaba",
  36.         "_type": "user",
  37.         "_id": "2",
  38.         "_score": 0.25316024,
  39.         "_source": {
  40.           "email": "john2@smith.com",
  41.           "first_name": "John2",
  42.           "last_name": "Smith",
  43.           "full_name": "John2 Smith",
  44.           "info": {
  45.             "age": 28,
  46.             "interests": [
  47.               "games",
  48.               "books"
  49.             ],
  50.             "address": "guangdong shenzhen baoan"
  51.           },
  52.           "created_at": "2019-06-07 08:30:10"
  53.         }
  54.       }
  55.     ]
  56.   }
  57. }

查询 last_name 包含 Smith，或者 full_name 包含 John 的用户。

  1. GET /alibaba/user/_search
  2. {
  3.   "query": {
  4.     "bool": {
  5.       "should": [
  6.         { "match": { "last_name": "Smith" } },
  7.         { "match": { "full_name": "John" } }
  8.       ]
  9.     }
  10.   }
  11. }

返回结果：

  1. {
  2.   "took": 7,
  3.   "timed_out": false,
  4.   "_shards": {
  5.     "total": 5,
  6.     "successful": 5,
  7.     "failed": 0
  8.   },
  9.   "hits": {
  10.     "total": 3,
  11.     "max_score": 0.5457982,
  12.     "hits": [
  13.       {
  14.         "_index": "alibaba",
  15.         "_type": "user",
  16.         "_id": "1",
  17.         "_score": 0.5457982,
  18.         "_source": {
  19.           "email": "john@smith.com",
  20.           "first_name": "John",
  21.           "last_name": "Smith",
  22.           "full_name": "John Smith",
  23.           "info": {
  24.             "age": 25,
  25.             "interests": [
  26.               "games",
  27.               "musics"
  28.             ],
  29.             "address": "guangdong shenzhen nanshan"
  30.           },
  31.           "created_at": "2019-06-06 08:30:10"
  32.         }
  33.       },
  34.       {
  35.         "_index": "alibaba",
  36.         "_type": "user",
  37.         "_id": "2",
  38.         "_score": 0.2876821,
  39.         "_source": {
  40.           "email": "john2@smith.com",
  41.           "first_name": "John2",
  42.           "last_name": "Smith",
  43.           "full_name": "John2 Smith",
  44.           "info": {
  45.             "age": 28,
  46.             "interests": [
  47.               "games",
  48.               "books"
  49.             ],
  50.             "address": "guangdong shenzhen baoan"
  51.           },
  52.           "created_at": "2019-06-07 08:30:10"
  53.         }
  54.       },
  55.       {
  56.         "_index": "alibaba",
  57.         "_type": "user",
  58.         "_id": "3",
  59.         "_score": 0.2876821,
  60.         "_source": {
  61.           "email": "john3@smith.com",
  62.           "first_name": "John3",
  63.           "last_name": "Smith",
  64.           "full_name": "John3 Smith",
  65.           "info": {
  66.             "age": 35,
  67.             "interests": [
  68.               "sports",
  69.               "musics"
  70.             ],
  71.             "address": "guangdong shenzhen longhua"
  72.           },
  73.           "created_at": "2019-06-08 09:40:10"
  74.         }
  75.       }
  76.     ]
  77.   }
  78. }

总结说明

  • bool：表示联合查询，用来合并多种查询条件。
  • must：表示多个查询条件的肯定匹配，多个条件必须都满足，相当于 and。
  • should：表示多个查询条件的肯定匹配，多个条件只要有一个满足，相当于 or。
  • must_not：表示多个查询条件的否定匹配，多个条件必须都满足，相当于 and。
  • filter：用于快速过滤结果集。
  • 文档字段的内部字段，通过 . 号来访问，如 info.age。

全文搜索

这里，我们搜索 info.address 包含 “shenzhen baoan” 的用户。

  1. GET /alibaba/user/_search
  2. {
  3.     "query" : {
  4.         "match" : {
  5.             "info.address" : "shenzhen baoan"
  6.         }
  7.     }
  8. }

返回结果：

  1. {
  2.   "took": 5,
  3.   "timed_out": false,
  4.   "_shards": {
  5.     "total": 5,
  6.     "successful": 5,
  7.     "failed": 0
  8.   },
  9.   "hits": {
  10.     "total": 3,
  11.     "max_score": 0.5063205,
  12.     "hits": [
  13.       {
  14.         "_index": "alibaba",
  15.         "_type": "user",
  16.         "_id": "2",
  17.         "_score": 0.5063205,
  18.         "_source": {
  19.           "email": "john2@smith.com",
  20.           "first_name": "John2",
  21.           "last_name": "Smith",
  22.           "full_name": "John2 Smith",
  23.           "info": {
  24.             "age": 28,
  25.             "interests": [
  26.               "games",
  27.               "books"
  28.             ],
  29.             "address": "guangdong shenzhen baoan"
  30.           },
  31.           "created_at": "2019-06-07 08:30:10"
  32.         }
  33.       },
  34.       {
  35.         "_index": "alibaba",
  36.         "_type": "user",
  37.         "_id": "1",
  38.         "_score": 0.25316024,
  39.         "_source": {
  40.           "email": "john@smith.com",
  41.           "first_name": "John",
  42.           "last_name": "Smith",
  43.           "full_name": "John Smith",
  44.           "info": {
  45.             "age": 25,
  46.             "interests": [
  47.               "games",
  48.               "musics"
  49.             ],
  50.             "address": "guangdong shenzhen nanshan"
  51.           },
  52.           "created_at": "2019-06-06 08:30:10"
  53.         }
  54.       },
  55.       {
  56.         "_index": "alibaba",
  57.         "_type": "user",
  58.         "_id": "3",
  59.         "_score": 0.25316024,
  60.         "_source": {
  61.           "email": "john3@smith.com",
  62.           "first_name": "John3",
  63.           "last_name": "Smith",
  64.           "full_name": "John3 Smith",
  65.           "info": {
  66.             "age": 35,
  67.             "interests": [
  68.               "sports",
  69.               "musics"
  70.             ],
  71.             "address": "guangdong shenzhen longhua"
  72.           },
  73.           "created_at": "2019-06-08 09:40:10"
  74.         }
  75.       }
  76.     ]
  77.   }
  78. }

可以发现，Elasticsearch 自动把要搜索匹配的字符串 “shenzhen baoan”，拆分成了两个词 “shenzhen” 和 “baoan”。然后再到 info.address 中进行全文搜索匹配。

搜索到的 3 条记录，默认是按照搜索排名分数降序排列的。

搜索排名分数（score），就是搜索结果相关性大小的评分，即文档与查询条件的匹配程度。相关性越大，搜索排名分数就越高，排名（排序）就越靠前。

这个概念在传统的关系型数据库中是无法想象的。

上面的查询语句，等价于下面的这种写法：

  1. GET /alibaba/user/_search
  2. {
  3.     "query" : {
  4.         "bool":{
  5.           "should": [
  6.             {"match" : {"info.address" : "shenzhen"}},
  7.             {"match" : {"info.address" : "baoan"}}
  8.           ]
  9.         }
  10.     }
  11. }

短语搜索

有时，我们确切地想要匹配多个单词或者短语（phrase）。这时，可以采用 match_phrase 来实现。

  1. GET /alibaba/user/_search
  2. {
  3.     "query" : {
  4.         "match_phrase" : {
  5.             "info.address" : "shenzhen baoan"
  6.         }
  7.     }
  8. }

返回结果：

  1. {
  2.   "took": 21,
  3.   "timed_out": false,
  4.   "_shards": {
  5.     "total": 5,
  6.     "successful": 5,
  7.     "failed": 0
  8.   },
  9.   "hits": {
  10.     "total": 1,
  11.     "max_score": 0.5063205,
  12.     "hits": [
  13.       {
  14.         "_index": "alibaba",
  15.         "_type": "user",
  16.         "_id": "2",
  17.         "_score": 0.5063205,
  18.         "_source": {
  19.           "email": "john2@smith.com",
  20.           "first_name": "John2",
  21.           "last_name": "Smith",
  22.           "full_name": "John2 Smith",
  23.           "info": {
  24.             "age": 28,
  25.             "interests": [
  26.               "games",
  27.               "books"
  28.             ],
  29.             "address": "guangdong shenzhen baoan"
  30.           },
  31.           "created_at": "2019-06-07 08:30:10"
  32.         }
  33.       }
  34.     ]
  35.   }
  36. }

高亮显示

有时，我们需要高亮显示匹配到的关键字。可以通过 highlight 来实现。

  1. GET /alibaba/user/_search
  2. {
  3.     "query" : {
  4.         "match_phrase" : {
  5.             "info.address" : "shenzhen baoan"
  6.         }
  7.     },
  8.     "highlight": {
  9.         "fields" : {
  10.             "info.address" : {}
  11.         }
  12.     }
  13. }

返回结果：

  1. {
  2.   "took": 77,
  3.   "timed_out": false,
  4.   "_shards": {
  5.     "total": 5,
  6.     "successful": 5,
  7.     "failed": 0
  8.   },
  9.   "hits": {
  10.     "total": 1,
  11.     "max_score": 0.5063205,
  12.     "hits": [
  13.       {
  14.         "_index": "alibaba",
  15.         "_type": "user",
  16.         "_id": "2",
  17.         "_score": 0.5063205,
  18.         "_source": {
  19.           "email": "john2@smith.com",
  20.           "first_name": "John2",
  21.           "last_name": "Smith",
  22.           "full_name": "John2 Smith",
  23.           "info": {
  24.             "age": 28,
  25.             "interests": [
  26.               "games",
  27.               "books"
  28.             ],
  29.             "address": "guangdong shenzhen baoan"
  30.           },
  31.           "created_at": "2019-06-07 08:30:10"
  32.         },
  33.         "highlight": {
  34.           "info.address": [
  35.             "guangdong <em>shenzhen</em> <em>baoan</em>"
  36.           ]
  37.         }
  38.       }
  39.     ]
  40.   }
  41. }

多字段搜索

有时，我们想要让同一个查询字符串同时应用到多个字段进行搜索匹配。可以采用 multi_match 来实现。

例如，查询 first_name 或者 full_name 包含 “smith” 的文档。

  1. GET /alibaba/user/_search
  2. {
  3.     "query" : {
  4.         "multi_match": {
  5.           "query": "smith",
  6.           "fields": ["first_name", "full_name"]
  7.         }
  8.     }
  9. }

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