Elasticsearch嵌套类型nested使用指南
Elasticsearch嵌套类型nested使用指南嵌套类型nested的特点
[*]可以存储数组对象
[*]每个对象独立存储为隐藏的子文档
嵌套类型nested和object类型的区别和应用场景
[*]nested
[*]每个对象独立存储为隐藏的子文档
[*]适合存储数组
[*]查询的时候有特定的语法 nested查询 且字段要用对象.字段名
[*]性能略低 因为要维护子文档
[*]object
[*]扁平化存储，数组中的对象相同字段会合并成数组
[*]适合存储单层的json对象
[*]查询的时候指定对象.字段名称即可
[*]查询性能高
嵌套类型nested如何使用
索引结构
"properties" : {
"create_time" : {
"format" : "yyyy-MM-dd HH:mm:ss Z||yyyy-MM-dd HH:mm:ss||yyyy-MM-dd HH:mm:ss.SSS Z||yyyy-MM-dd HH:mm:ss.SSS||yyyy-MM-dd HH:mm:ss,SSS||yyyy/MM/dd HH:mm:ss||yyyy-MM-dd HH:mm:ss,SSS Z||yyyy/MM/dd HH:mm:ss,SSS Z||epoch_millis||yyyy-MM-dd",
"index" : true,
"type" : "date",
"doc_values" : true
},
"title" : {
"index" : true,
"type" : "text"
},
"users" : {
"type" : "nested",
"properties" : {
"sex" : {
"type" : "keyword"
},
"age" : {
"type" : "integer"
},
"username" : {
"type" : "keyword"
}
}
}
}插入数据
POST cn_taoym_json_to_nested/_bulk
{"index":{}}
{"create_time":"2023-10-01 10:00:00","title":"第一条数据","users":[{"username":"user1","age":25,"sex":"male"}]}
{"index":{}}
{"create_time":"2023-10-02 14:30:00","title":"第二条数据","users":[{"username":"user2","age":30,"sex":"female"}]}
{"index":{}}
{"create_time":"2023-10-03 09:15:00","title":"第三条数据","users":[{"username":"user3","age":28,"sex":"male"},{"username":"user4","age":22,"sex":"female"}]}
{"index":{}}
{"create_time":"1696300800000","title":"第四条数据（时间戳格式）","users":[{"username":"user5","age":35,"sex":"male"}]}
{"index":{}}
{"create_time":"2023/10/05 16:45:00","title":"第五条数据（不同日期格式）","users":[{"username":"user6","age":27,"sex":"female"}]}查询username为user3的数据
GET cn_taoym_json_to_nested/_search
{
"query": {
"nested": {
"path": "users",
"query": {
"term": {
"users.username": {
"value": "user3"
}
}
},
"inner_hits": {}
}
}
}结果集
{
"took" : 2,
"timed_out" : false,
"_shards" : {
"total" : 4,
"successful" : 4,
"skipped" : 0,
"failed" : 0
},
"hits" : {
"total" : 1,
"max_score" : 0.9808291,
"hits" : [ {
"_index" : "cn_taoym_json_to_nested",
"_type" : "_doc",
"_id" : "EKfHp5gBCQbF-O0GPRhA",
"_score" : 0.9808291,
"_source" : {
"create_time" : "2023-10-03 09:15:00",
"title" : "第三条数据",
"users" : [ {
"sex" : "male",
"age" : 28,
"username" : "user3"
}, {
"sex" : "female",
"age" : 22,
"username" : "user4"
} ]
},
"inner_hits" : {
"users" : {
"hits" : {
"hits" : [ {
"_index" : "cn_taoym_json_to_nested",
"_type" : "_doc",
"_source" : {
"sex" : "male",
"age" : 28,
"username" : "user3"
},
"_id" : "EKfHp5gBCQbF-O0GPRhA",
"_nested" : {
"field" : "users",
"offset" : 0
},
"_score" : 0.9808291
} ],
"total" : 1,
"max_score" : 0.9808291
}
}
}
} ]
}
}"inner_hits": {}的作用是将嵌套查询中复合预期的数据单独收集起来。source里面存储的是原数据，里面自然包含所有数据的
来源：程序园用户自行投稿发布，如果侵权，请联系站长删除
免责声明：如果侵犯了您的权益，请联系站长，我们会及时删除侵权内容，谢谢合作！
页:
[1]