Elasticsearch nested嵌套类型

梦里梦外; 2022-09-09 12:53 230阅读 0赞

第一次接触es,感觉啥啥都是懵逼状态,不得不吐槽一下,出了问题网上写的那些文章真的是看不懂,要么代码不全,要么就是各种抄,根本结局不了问题,还是决定自己写一个吧,没准哪天就帮别人节省了时间.  
话不多说,这里使用的版本是7.12.1,查看es版本方法:  
直接在浏览器访问es端口号就行 ps:搞了一天才发现看的是2.0的api 我吐了  
![在这里插入图片描述][watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA56m65Z-O5pen5qKm5Lio_size_17_color_FFFFFF_t_70_g_se_x_16]  
博主现在查看的api是7.14版本的(直接看最新的了)  
为什么要用nested嵌套结构呢?具体可以看官网的解释,这里就不在多做赘述了:  
[https://www.elastic.co/guide/en/elasticsearch/reference/7.14/nested.html][https_www.elastic.co_guide_en_elasticsearch_reference_7.14_nested.html]

简单来说就是需要一个多层嵌套的对象结构,例如:  
公司下面有部门员工,员工下面有所属项目,都是一对多的关系,后面的代码也是使用的这个逻辑(可能有点不太合理,但是大致是这么个意思)

**公司:  
\_\_\_\_部门名称  
\_\_\_\_部门员工:  
\_\_\_\_\_\_\_\_id  
\_\_\_\_\_\_\_\_姓名  
\_\_\_\_\_\_\_\_年龄  
\_\_\_\_\_\_\_\_所属项目:  
\_\_\_\_\_\_\_\_\_\_\_\_项目名称**

直接上代码

1.声明结构

PUT  localhost:9200/test_mapping7
    
    { 
        "mappings": { 
            "properties":{ 
                "group": { "type": "text"},
                "user":{ 
                    "type": "nested",  //嵌套类型type应为nested
                    "properties":{ 
                        "id": { "type": "keyword"},
                        "name":{ "type": "text"},
                        "age":{  "type": "short"},
                        "project":{ 
                            "type": "nested",
                            "properties":{ 
                                "name": { "type": "text"}
                                }
                            
                        }
                    }
                    
                }
            }      
        }    
    }

nested类型结构的属性应用properties表示,以下是官网api  
![在这里插入图片描述][watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA56m65Z-O5pen5qKm5Lio_size_20_color_FFFFFF_t_70_g_se_x_16]  
2.声明成功后我们可以查询一下声明的结构

GET localhost:9200/test_mapping7?pretty  //pretty是输出json格式化后的数据
    
    {                                                 
      "test_mapping7" : {                             
        "aliases" : {  },                             
        "mappings" : {                                
          "properties" : {                            
            "group" : {                               
              "type" : "text"                        
            },                                       
            "user" : {                                
              "type" : "nested",                     
              "properties" : {                        
                "age" : {                             
                  "type" : "short"                   
                },                                   
                "id" : {                              
                  "type" : "keyword"                 
                },                                   
                "name" : {                            
                  "type" : "text"                    
                },                                   
                "project" : {                         
                  "type" : "nested",                 
                  "properties" : {                    
                    "name" : {                        
                      "type" : "text"                
                    }                                
                  }                                  
                }                                    
              }                                      
            }                                        
          }                                          
        },                                           
        "settings" : {                                
          "index" : {                                 
            "routing" : {                             
              "allocation" : {                        
                "include" : {                         
                  "_tier_preference" : "data_content"
                }                                    
              }                                      
            },                                       
            "number_of_shards" : "1",                
            "provided_name" : "test_mapping7",       
            "creation_date" : "1630464120543",       
            "number_of_replicas" : "1",              
            "uuid" : "stKB9OdESUmnqJwBKOK-pQ",       
            "version" : {                             
              "created" : "7120199"                  
            }                                        
          }                                          
        }                                            
      }                                              
    }

3.插入数据  
**重点: 插入数据这块必须在index名后面加上/\_doc/ , 本身这里应该是设置type的字段,但是在实际插入数据时,用自定义的stu,class等都会报错,难道只能插入doc类型? ps:正常猜想是在mapping中没有设置最外层的type,但是实际操作时声明type会报错**

POST localhost:9200/test_mapping7/_doc/1 
    
    { 
        "group": "研发",
        "user":[{ 
                "id": 1,
                "name": "zhangsan",
                "age": 12,
                "project":[{ 
                    "name": "pro1"
                }]
            },
            { 
                "id": 2,
                "name": "lisi",
                "age": 15,
                "project":[{ 
                    "name": "pro12"
                }]
            }]
    }
    
    result:
    
    { 
        "_index": "test_mapping7",
        "_type": "_doc",
        "_id": "2",
        "_version": 1,
        "result": "created",
        "_shards": { 
            "total": 1,
            "successful": 1,
            "failed": 0
        },
        "_seq_no": 1,
        "_primary_term": 1
    }

再插入一条

POST localhost:9200/test_mapping7/_doc/2
    
    { 
        "group": "市场",
        "user":[{ 
                "id": 3,
                "name": "xiaomei",
                "age": 21,
                "project":[{ 
                    "name": "pro3"
                }]
            },
            { 
                "id": 4,
                "name": "xiaoxue",
                "age": 25,
                "project":[{ 
                    "name": "pro4"
                }]
            }]
    }
    
    result:
    
    { 
        "_index": "test_mapping7",
        "_type": "_doc",
        "_id": "2",
        "_version": 1,
        "result": "created",
        "_shards": { 
            "total": 2,
            "successful": 1,
            "failed": 0
        },
        "_seq_no": 1,
        "_primary_term": 1
    }

查询一下插入的数据

GET localhost:9200/test_mapping7/_search?pretty
    
    {                                          
      "took" : 3,                             
      "timed_out" : false,                    
      "_shards" : {                            
        "total" : 1,                          
        "successful" : 1,                     
        "skipped" : 0,                        
        "failed" : 0                          
      },                                      
      "hits" : {                               
        "total" : {                            
          "value" : 2,                        
          "relation" : "eq"                   
        },                                    
        "max_score" : 1.0,                    
        "hits" : [                            
          {                                    
            "_index" : "test_mapping7",       
            "_type" : "_doc",                 
            "_id" : "1",                      
            "_score" : 1.0,                   
            "_source" : {                      
              "group" : "研发",                 
              "user" : [                      
                {                              
                  "id" : 1,                   
                  "name" : "zhangsan",        
                  "age" : 12,                 
                  "project" : [               
                    {                          
                      "name" : "pro1"         
                    }                         
                  ]                           
                },                            
                {                              
                  "id" : 2,                   
                  "name" : "lisi",            
                  "age" : 14,                 
                  "project" : [               
                    {                          
                      "name" : "pro12"        
                    }                         
                  ]                           
                }                             
              ]                               
            }                                 
          },                                  
          {                                    
            "_index" : "test_mapping7",       
            "_type" : "_doc",                 
            "_id" : "2",                      
            "_score" : 1.0,                   
            "_source" : {                      
              "group" : "市场",                 
              "user" : [                      
                {                              
                  "id" : 3,                   
                  "name" : "xiaomei",         
                  "age" : 21,                 
                  "project" : [               
                    {                          
                      "name" : "pro3"         
                    }                         
                  ]                           
                },                            
                {                              
                  "id" : 4,                   
                  "name" : "xiaoxue",         
                  "age" : 25,                 
                  "project" : [               
                    {                          
                      "name" : "pro4"         
                    }                         
                  ]                           
                }                             
              ]                               
            }                                 
          }                                   
        ]                                     
      }                                       
    }

4.查询

首先查询一下name=zhangsan的index

GET localhost:9200/test_mapping7/_search
    
    { 
        "query": { 
            "nested":{ 
                "path": "user",
                "query": { 
                    "bool":{ 
                        "must": [
                            { "match": { "user.name":"zhangsan"}}
                        ]
                    }
                }
            }
        }
    }
    
    result:
    
    { 
        "took": 2,
        "timed_out": false,
        "_shards": { 
            "total": 1,
            "successful": 1,
            "skipped": 0,
            "failed": 0
        },
        "hits": { 
            "total": { 
                "value": 1,
                "relation": "eq"
            },
            "max_score": 1.2039728,
            "hits": [
                { 
                    "_index": "test_mapping7",
                    "_type": "_doc",
                    "_id": "1",
                    "_score": 1.2039728,
                    "_source": { 
                        "group": "研发",
                        "user": [
                            { 
                                "id": 1,
                                "name": "zhangsan",
                                "age": 12,
                                "project": [
                                    { 
                                        "name": "pro1"
                                    }
                                ]
                            },
                            { 
                                "id": 2,
                                "name": "lisi",
                                "age": 14,
                                "project": [
                                    { 
                                        "name": "pro12"
                                    }
                                ]
                            }
                        ]
                    }
                }
            ]
        }
    }

可以看到直接返回了整个doc1对象,符合预期结果

那么我们如果查询条件是project.name=pro4呢?划重点  
**nested.path必须是从外层开始写: user.project,不可以直接写project**  
**match条件也要从最外层开始写 user.project.name=pro4,不可以直接写project.name=pro4**

POST localhost:9200/test_mapping7/_search
    
    { 
        "query": { 
            "nested":{ 
                "path": "user.project",
                "query": { 
                    "bool":{ 
                        "must": [
                            { "match": { "user.project.name":"pro4"}}
                        ]
                    }
                }
            }
        }
    }
    
    result:
    
    { 
        "took": 2,
        "timed_out": false,
        "_shards": { 
            "total": 1,
            "successful": 1,
            "skipped": 0,
            "failed": 0
        },
        "hits": { 
            "total": { 
                "value": 1,
                "relation": "eq"
            },
            "max_score": 1.2039728,
            "hits": [
                { 
                    "_index": "test_mapping7",
                    "_type": "_doc",
                    "_id": "2",
                    "_score": 1.2039728,
                    "_source": { 
                        "group": "市场",
                        "user": [
                            { 
                                "id": 3,
                                "name": "xiaomei",
                                "age": 21,
                                "project": [
                                    { 
                                        "name": "pro3"
                                    }
                                ]
                            },
                            { 
                                "id": 4,
                                "name": "xiaoxue",
                                "age": 25,
                                "project": [
                                    { 
                                        "name": "pro4"
                                    }
                                ]
                            }
                        ]
                    }
                }
            ]
        }
    }

成功命中  
未完待续,欢迎补充指正

[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA56m65Z-O5pen5qKm5Lio_size_17_color_FFFFFF_t_70_g_se_x_16]: /images/20220829/783375c899df4ed3978704151c53f381.png
[https_www.elastic.co_guide_en_elasticsearch_reference_7.14_nested.html]: https://www.elastic.co/guide/en/elasticsearch/reference/7.14/nested.html
[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA56m65Z-O5pen5qKm5Lio_size_20_color_FFFFFF_t_70_g_se_x_16]: /images/20220829/6221c176dae844a993233302a5dfebfc.png