ES中的数据类型学习之ARRAY

Arrays | Elasticsearch Guide [7.17] | Elastic

中文翻译 ：Array · Elasticsearch 5.4 中文文档 · 看云

Arrays

In Elasticsearch, there is no dedicated array data type. Any field can contain zero or more values by default, however, all values in the array must be of the same data type. For instance:

• an array of strings: [ "one", "two" ]
• an array of integers: [ 1, 2 ]
• an array of arrays: [ 1, [ 2, 3 ]] which is the equivalent of [ 1, 2, 3 ]
• an array of objects: [ { "name": "Mary", "age": 12 }, { "name": "John", "age": 10 }]

NOTE

Arrays of objects

Arrays of objects do not work as you would expect: you cannot query each object independently of the other objects in the array. If you need to be able to do this then you should use the nested data type instead of the object data type.

This is explained in more detail in Nested.

主要说了

1.es里没有专用的array类型，实际类型是keyword 或者object类型。

2.es的array只能存相同类型的数据

3.es这里的数组不是真正的数组，如果要用真正的数组，推荐用nested数据类型。

还有一些就不复制粘贴了。直接实战开始

PUT my-index-000001/_doc/1
{
  "message": "some arrays in this document...",
  "tags":  [ "elasticsearch", "wow" ],
  "lists": [
    {
      "name": "prog_list",
      "description": "programming list"
    },
    {
      "name": "cool_list",
      "description": "cool stuff list"
    }
  ]
}

PUT my-index-000001/_doc/2
{
  "message": "no arrays in this document...",
  "tags":  "elasticsearch",
  "lists": {
    "name": "prog_list",
    "description": "programming list"
  }
}

PUT my-index-000001/_doc/2
{
  "message": "no arrays in this document...",
  "tags":  "elasticsearch",
  "lists": {
    "name": "prog_list",
    "description": "programming list"
  }
}

查看下映射 GET my-index-000001/_mapping

发现属性实际为keyword 和properties

 测试下查询

GET my-index-000001/_search
{
  "query": {
    "match": {
      "tags": "elasticsearch"
    }
  }
}

发现查出两条数据没有问题。

但是查询 对象中的多个属性的时候就会出现问题

GET my-index-000001/_search
{
  "query": {
    "bool": {
      "must": [
        { "match": { "lists.name": "prog_list" } },
        {"match": {"lists.description": "cool stuff list"}
        }
      ]
    }
  }
}

这个时候就需要用到nested了。