• Elasticsearch语法知多少之Multi_match query

    目录

    目标

    ES版本信息

    官方文档

    新增测试数据

    基本语法实战

    基本格式

    通配符匹配多个字段

    逻辑操作符

    设置评分权重

    multi_match多种类型实战

    best_fields最佳字段（默认）

    most_fields最多字段

    跨字段匹配

    目标

    掌握多匹配查询，包含对多匹配查询的类型分析和应用。

    ES版本信息

    7.17.5

    官方文档

    Multi-match queryhttps://www.elastic.co/guide/en/elasticsearch/reference/7.9/query-dsl-multi-match-query.html

    新增测试数据

    1. PUT /boss_db
    2. {
    3.     "settings": {
    4.     "index": {
    5.       "analysis.analyzer.default.type": "ik_max_word"
    6.     }
    7.   }
    8. }
    9.  
    10. PUT /boss_db/_bulk
    11. {"index":{"_id":"1"}}
    12. {"company":"星耀科技有限公司","min_num":0,"max_num":20,"province":"广东省","city":"深圳市","county":"南山区","post":"前端开发实习生","min_salary":10,"max_salary":16,"qualification":"本科","min_work_time":3,"max_work_time":5,"skill":["html","css","vue","js"]}
    13. {"index":{"_id":"2"}}
    14. {"company":"恒和科技有限公司","min_num":100,"max_num":500,"province":"广东省","city":"广州市","county":"天河区","post":"JAVA开发工程师","min_salary":20,"max_salary":30,"qualification":"硕士","min_work_time":1,"max_work_time":3,"skill":["k8s","springboot","mybatis","微服务"]}
    15. {"index":{"_id":"3"}}
    16. {"company":"天心科技有限公司","min_num":2000,"max_num":5000,"province":"广东省","city":"广州市","county":"天河区","post":"JAVA架构师","min_salary":40,"max_salary":50,"qualification":"博士","min_work_time":3,"max_work_time":5,"skill":["mybatis","spring","kafka","微服务"]}
    17. {"index":{"_id":"4"}}
    18. {"company":"黄河科技有限公司","min_num":2000,"max_num":5000,"province":"广东省","city":"广州市","county":"天河区","post":"JAVA","min_salary":40,"max_salary":50,"qualification":"博士","min_work_time":3,"max_work_time":5,"skill":["es","mysql","分布式","soa"]}
    19. {"index":{"_id":"5"}}
    20. {"company":"长江科技有限公司","min_num":2000,"max_num":5000,"province":"广东省","city":"深圳市","county":"龙岗区","post":"资深大数据开发工程师","min_salary":40,"max_salary":50,"qualification":"博士","min_work_time":0,"max_work_time":5,"skill":["redis","kafka","mq","数据结构"]}
    21. {"index":{"_id":"6"}}
    22. {"company":"黄山科技有限公司","min_num":2000,"max_num":5000,"province":"广东省","city":"深圳市","county":"龙岗区","post":"前端开发","min_salary":20,"max_salary":30,"qualification":"大专","min_work_time":0,"max_work_time":5,"skill":["html","css","js","vue"]}
    23. {"index":{"_id":"7"}}
    24. {"company":"黄山科技有限公司","min_num":2000,"max_num":5000,"province":"广东省","city":"深圳市","county":"龙岗区","post":"前端开发实习生","min_salary":10,"max_salary":13,"qualification":"不限","min_work_time":0,"max_work_time":5}
    25. {"index":{"_id":"8"}}
    26. {"company":"银河大数据科技有限公司","min_num":2000,"max_num":5000,"province":"广东省","city":"深圳市","county":"龙岗区","post":"大数据实习生","min_salary":10,"max_salary":13,"qualification":"不限","min_work_time":0,"max_work_time":5,"skill":["电商","spring","容器技术","微服务技术"]}
    27. {"index":{"_id":"9"}}
    28. {"company":"银河大数据科技有限公司","min_num":2000,"max_num":5000,"province":"广东省","city":"深圳市","county":"龙岗区","post":"JAVA实习生","min_salary":30,"max_salary":60,"qualification":"本科","min_work_time":0,"max_work_time":5,"skill":["数据结构","k8s","云原生技术","电商"]}
    29.  
    30. PUT /blog_db
    31. {
    32.     "settings": {
    33.     "index": {
    34.       "analysis.analyzer.default.type": "ik_max_word"
    35.     }
    36.   }
    37. }
    38.  
    39. PUT /blog_db/_bulk
    40. {"index":{"_id":"1"}}
    41. {"title":"kafka入门手册","content":"kafka命令、集群、优化"}
    42. {"index":{"_id":"2"}}
    43. {"title":"kafka命令手册","content":"命令详情、命令实战"}

    基本语法实战

    基本格式

    需求：例如：在招聘网搜索栏中的关键词匹配职位和公司。这里分别输入"天心"和"大数据"进行搜索。

    1. GET boss_db/_search
    2. {
    3.   "query": {
    4.     "multi_match" : {
    5.       "query":    "天心", 
    6.       "fields": [ "company", "post" ] 
    7.     }
    8.   }
    9. }
    10.  
    11. GET boss_db/_search
    12. {
    13.   "query": {
    14.     "multi_match" : {
    15.       "query":    "大数据", 
    16.       "fields": [ "company", "post" ] 
    17.     }
    18.   }
    19. }

    通配符匹配多个字段

    需求：凡是字段名称包含"work_time"的都作为匹配字段。

    1. GET boss_db/_search
    2. {
    3.   "query": {
    4.     "multi_match" : {
    5.       "query":    5, 
    6.       "fields": [ "*work_time" ] 
    7.     }
    8.   }
    9. }

    逻辑操作符

    需求一：搜索条件是"前端开发实习生"，要求所有分词都匹配。

    1. GET boss_db/_search
    2. {
    3.   "query": {
    4.     "multi_match" : {
    5.       "query":    "前端开发实习生", 
    6.       "fields": [ "post" ] 
    7.       , "operator": "and"
    8.     }
    9.   }
    10. }

    需求二：搜索条件是"前端开发实习生"，要求只要有分词匹配就符合条件。

    1. GET boss_db/_search
    2. {
    3.   "query": {
    4.     "multi_match" : {
    5.       "query":    "前端开发实习生", 
    6.       "fields": [ "post" ] 
    7.       , "operator": "or"
    8.     }
    9.   }
    10. }

    设置评分权重

    需求：关键词为"大数据"，要求匹配字段是公司和职位，且评分要求职位字段权重大于公司字段权重。

    1. #不处理权重
    2. GET boss_db/_search
    3. {
    4.  
    5.   "query": {
    6.     "multi_match" : {
    7.       "query":    "大数据", 
    8.       "fields": ["company", "post" ] 
    9.     }
    10.   }
    11. }
    12.  
    13. #职位评分分数乘以4。
    14. GET boss_db/_search
    15. {
    16.  
    17.   "query": {
    18.     "multi_match" : {
    19.       "query":    "大数据", 
    20.       "fields": ["company", "post^4" ] 
    21.     }
    22.   }
    23. }

    multi_match多种类型实战

    best_fields最佳字段（默认）

    作用：从所有字段被搜索的字段中找到最重要的字段。比如：关键词为"棕色的狐狸"；a字段包含棕色的狐狸，b字段只包含棕色的，c字段只包含狐狸。此时ES认为a字段是最佳字段。tie_breaker的取值的范围是[1,0]，默认值为0，即只考虑最佳字段的分数。如果对它进行设置：

    1. 设置0表示：总分=最佳字段的分数。
    2. 设置0
    3. 设置tie_breaker=1表示：所有字段分数权重一样，相当于没有最佳字段。总分=所有字段相加。

    需求：搜索关键词为"kafka命令"，同时匹配标题和内容，优先标题权重。

    分析：如果不设置tie_breaker，根据关键词"kafka命令"匹配，两个文档的最终得分相等，因为id小的排在前面。但是按照业务来看，明显id=2的文档更符合逻辑，所以这里需要将其他字段的分数也算进来一部分即可，这里我设置算进来0.1倍分数。

    1. GET /blog_db/_search
    2. {
    3.   "query": {
    4.     "multi_match": {
    5.       "query": "kafka命令",
    6.       "type": "best_fields",
    7.       "fields": [
    8.         "title",
    9.         "content"
    10.       ],
    11.       "tie_breaker": 0.1
    12.     }
    13.   }
    14. }

    most_fields最多字段

    相当于best_fields类型，tie_breaker属性设置为1的效果。说明该类型更适合处理字段评分权重相同的场景。这里不做演示，具体同上，tie_breaker设置为1的情况。

    跨字段匹配

    需求：搜索公司所在区县是"天河区"，且应聘学历为"硕士"的数据。

    1. GET boss_db/_search
    2. {
    3.   "query": {
    4.     "multi_match": {
    5.       "query": "天河区硕士",
    6.       "type": "cross_fields",
    7.       "fields": [
    8.         "county",
    9.         "qualification"
    10.       ],
    11.       "operator": "and"
    12.     }
    13.   }
    14. }

    分析：所有分词必须至少出现在一个字段中，文档才能匹配。它与copy_to类似，但是copy_to需要额外存储，而cross_fields方式不需要额外存储且可以设置字段权重。个人觉得这种方式更适合在查询地名和英文姓名使用。

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  • 原文地址：https://blog.csdn.net/qq_39706570/article/details/126275796