Detailed Explanation of Elasticsearch Mapping Parameters fields

Elasticsearch mapping parameter fields

fields

It is often useful to index the same fields in different ways for different purposes. This is also the purpose of multi-fields. For example, a string field can be mapped to an text field for full-text search, or to an keyword field for sorting or aggregation.

PUT my_index
{
  "mappings": {
    "_doc": {
      "properties": {
        "city": {
          "type": "text",
          "fields": {
            "raw": { 
              "type":  "keyword"
            }
          }
        }
      }
    }
  }
}

note The city. raw field is the keyword version of the city field.

GET my_index/_search
{
  "query": {
    "match": {
      "city": "york" 
    }
  },
  "sort": {
    "city.raw": "asc" 
  },
  "aggs": {
    "Cities": {
      "terms": {
        "field": "city.raw" 
      }
    }
  }
}

note The city field is used for full-text searches.

note : city. raw for sorting and aggregation.

Multiple fields cannot modify the original _ source field.

The fields setting allows for different settings for fields with the same name in the same index. You can use the PUT mapping API to add a new multi-field to an existing field.

Multiple Fields with Multiple Analyses

Another application scenario for multiple fields is to analyze the same fields in different ways for better correlation.

PUT my_index
{
  "mappings": {
    "_doc": {
      "properties": {
        "text": { 
          "type": "text",
          "fields": {
            "english": { 
              "type":     "text",
              "analyzer": "english"
            }
          }
        }
      }
    }
  }
}

note The text. field field uses the english parser.

Implementation of fields by elasticsearch Annotation

mapping effect:

"label": {
            "type": "keyword",
            "fields": {
              "IKS": {
                "type": "text",
                "analyzer": "ikIndexAnalyzer"
              }
            }
          }

@Column(name = " Label ")
    @MultiField(
            mainField = @Field(type = FieldType.Keyword),
            otherFields = {
                    @InnerField(suffix = "IKS", type = FieldType.Text, analyzer = "ikIndexAnalyzer")
            }
    )
    protected String label;