ElasticSearch 字段类型

普通类型

  • binary: Binary value encoded as a Base64 string.

    The binary type accepts a binary value as a Base64 encoded string. The field is not stored by default and is not searchable:

    BINARY类型接受二进制值作为Base64编码字符串。默认情况下，该字段不存储且不可搜索

    The following parameters are accepted by binary fields:

    参数名称 说明
    doc_values 字段是否应该以跨列方式存储在磁盘上，以便以后可以用于排序、聚合或编写脚本？
    接受true或false
    store 字段值是否应与_source字段分开存储和检索。
    接受true或false    		 
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    PUT my-index-000001
    {
      "mappings": {
        "properties": {
          "name": {
            "type": "text"
          },
          "blob": {
            "type": "binary",
            "doc_values": false,
            "store": false
          }
        }
      }
    }

    PUT my-index-000001/_doc/1
    {
      "name": "Some binary blob",
      "blob": "U29tZSBiaW5hcnkgYmxvYg==" // Base64编码的二进制值不能嵌入换行符\n
    }

  • boolean: true and false values.

    Boolean fields accept JSON true and false values, but can also accept strings which are interpreted as either true or false:

    参数 说明
    False values false, "false", "" (empty string)
    True values true, "true"

    The following parameters are accepted by boolean fields:

    参数 说明
    boost Mapping field-level query time boosting. Accepts a floating point number, defaults to 1.0.
    doc_values Should the field be stored on disk in a column-stride fashion, so that it can later be used for sorting, aggregations, or scripting? Accepts true (default) or false.
    index Should the field be searchable? Accepts true (default) and false.
    null_value Accepts any of the true or false values listed above. The value is substituted for any explicit null values. Defaults to null, which means the field is treated as missing.
    store Whether the field value should be stored and retrievable separately from the _source field. Accepts true or false (default).
    meta Metadata about the field.

  • Keywords: The keyword family, including keyword, constant_keyword, and wildcard.

  • Numbers: Numeric types, such as long and double, used to express amounts

别名

  • alias: Defines an alias for an existing field.

    An alias mapping defines an alternate name for a field in the index. The alias can be used in place of the target field in search requests, and selected other APIs like field capabilities.

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    PUT trips
    {
      "mappings": {
        "properties": {
          "distance": {
            "type": "long"
          },
          // 设置route_length_miles为distance的别名
          "route_length_miles": {
            "type": "alias",
            "path": "distance" // The path to the target field. Note that this must be the full path, including any parent objects (e.g. object1.object2.field). 目标字段必须是完整路径
          },
          "transit_mode": {
            "type": "keyword"
          }
        }
      }
    }

    GET _search
    {
      "query": {
        "range" : {
          "route_length_miles" : {
            "gte" : 39
          }
        }
      }
    }

  • 别名的作用

    Almost all components of the search request accept field aliases. In particular, aliases can be used in queries, aggregations, and sort fields, as well as when requesting docvalue_fields, stored_fields, suggestions, and highlights. Scripts also support aliases when accessing field values.

    搜索请求的几乎所有组件都接受字段别名。具体地说，别名可以在查询、聚合和排序字段中使用，也可以在请求docvalue_field、stored_field、suggestions和Highlight时使用。脚本还支持在访问字段值时使用别名。

  • 别名的限制

    There are a few restrictions on the target of an alias:

    • The target must be a concrete field, and not an object or another field alias. 目标必须是具体字段，而不是对象或其他字段别名。
    • The target field must exist at the time the alias is created. 创建别名时，目标字段必须存在。
    • If nested objects are defined, a field alias must have the same nested scope as its target. 如果定义了嵌套对象，字段别名必须与其目标具有相同的嵌套作用域。

    Additionally, a field alias can only have one target. This means that it is not possible to use a field alias to query over multiple target fields in a single clause.

    An alias can be changed to refer to a new target through a mappings update. A known limitation is that if any stored percolator queries contain the field alias, they will still refer to its original target.

    别名的目标有几个限制：

    • 目标必须是具体字段，而不是对象或其他字段别名。
    • 创建别名时，目标字段必须存在。
    • 如果定义了嵌套对象，字段别名必须与其目标具有相同的嵌套作用域。

    此外，一个字段别名只能有一个目标。这意味着不能在单个子句中使用字段别名查询多个目标字段。

    可以通过映射更新将别名更改为引用新目标。一个已知的限制是，如果任何存储的过滤器查询包含字段别名，它们仍将引用其原始目标。

    Writes to field aliases are not supported: attempting to use an alias in an index or update request will result in a failure. Likewise, aliases cannot be used as the target of copy_to or in multi-fields.Because alias names are not present in the document source, aliases cannot be used when performing source filtering.

    不支持写入字段别名：尝试在索引或更新请求中使用别名将导致失败。同样，别名不能作为copy_to的目标，也不能多字段使用，由于别名不存在于文档源中，因此在执行源筛选时不能使用别名。

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    错误示例
    GET /_search
    {
      "query" : {
        "match_all": {}
      },
      "_source": "route_length_miles"
    }

日期

  • Dates: Date types, including date and date_nanos.

    JSON doesn’t have a date data type, so dates in Elasticsearch can either be:

    • strings containing formatted dates, e.g. "2015-01-01" or "2015/01/01 12:10:30". 日期格式的字符串
    • a number representing milliseconds-since-the-epoch. 毫秒级的时间戳
      • Values for milliseconds-since-the-epoch must be non-negative. Use a formatted date to represent dates before 1970. 从纪元开始的毫秒数的值必须为非负数。使用格式化日期表示1970年前的日期。
    • a number representing seconds-since-the-epoch 秒级的时间戳

    Date formats can be customised, but if no format is specified then it uses the default:

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    "strict_date_optional_time||epoch_millis"
    PUT my-index-000001
    {
      "mappings": {
        "properties": {
          "date": {
            "type":   "date",
            "format": "strict_date_optional_time||epoch_second"
          }
        }
      }
    }

    The following parameters are accepted by date fields:

    boost Mapping field-level query time boosting. Accepts a floating point number, defaults to 1.0.
    doc_values Should the field be stored on disk in a column-stride fashion, so that it can later be used for sorting, aggregations, or scripting? Accepts true (default) or false.
    format The date format(s) that can be parsed. Defaults to `strict_date_optional_time
    locale The locale to use when parsing dates since months do not have the same names and/or abbreviations in all languages. The default is the ROOT locale,
    ignore_malformed If true, malformed numbers are ignored. If false (default), malformed numbers throw an exception and reject the whole document.
    index Should the field be searchable? Accepts true (default) and false.
    null_value Accepts a date value in one of the configured format’s as the field which is substituted for any explicit null values. Defaults to null, which means the field is treated as missing.
    store Whether the field value should be stored and retrievable separately from the _source field. Accepts true or false (default).
    meta Metadata about the field.

对象类型

  • object: A JSON object.
  • flattened: An entire JSON object as a single field value.将整个JSON对象作为单个字段值。
  • nested: A JSON object that preserves the relationship between its subfields. 保留其子字段之间关系的JSON对象。
  • join: Defines a parent/child relationship for documents in the same index. 为同一索引中的文档定义父/子关系。

特定类型

  • Range: Range types, such as long_range, double_range, date_range, and ip_range.
  • ip: IPv4 and IPv6 addresses.
  • version: Software versions.
  • murmur3: Compute and stores hashes of values. 计算并存储值的散列。

聚合数据类型

  • aggregate_metric_double: Pre-aggregated metric values.
  • histogram: Pre-aggregated numerical values in the form of a histogram. 以直方图形式预先聚合的数值。

文本数据类型

  • text: Analyzed, unstructured text.
  • annotated-text: Text containing special markup. Used for identifying named entities.
  • completion: Used for auto-complete suggestions.
  • search_as_you_type: text-like type for as-you-type completion.
  • token_count: A count of tokens in a text.

文档排名类型

  • dense_vector: Records dense vectors of float values.

  • sparse_vector: Records sparse vectors of float values.

  • rank_feature: Records a numeric feature to boost hits at query time.

  • rank_features: Records numeric features to boost hits at query time.

空间数据类型

  • geo_point: Latitude and longitude points.

  • geo_shape: Complex shapes, such as polygons.

  • point: Arbitrary cartesian points.

  • shape: Arbitrary cartesian geometries.

数组

  • 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.

在Elasticsearch中，没有专用的array数据类型。默认情况下，任何字段都可以包含零个或多个值，但是数组中的所有值必须属于相同的数据类型。

When adding a field dynamically, the first value in the array determines the field type. All subsequent values must be of the same data type or it must at least be possible to coerce subsequent values to the same data type.

Arrays with a mixture of data types are not supported: [ 10, "some string" ]

An array may contain null values, which are either replaced by the configured null_value or skipped entirely. An empty array [] is treated as a missing field — a field with no values.

动态添加字段时，数组中的第一个值确定字段类型。所有后续值必须具有相同的数据类型，或者必须至少可以将后续值强制为相同的数据类型。
不支持混合数据类型的数组：[10，“某些字符串”]。
数组可以包含空值，可以由配置的NULL_VALUE替换，也可以完全跳过。空数组[]被视为缺少的字段 - 没有值的字段。