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_field_names field
edit_field_names
field
editThe _field_names
field indexes the names of every field in a document that
contains any value other than null
. This field is used by the
exists
and missing
queries to find documents that either have or don’t have any non-null
value
for a particular field.
The value of the _field_name
field is accessible in queries, aggregations, and
scripts:
# Example documents PUT my_index/my_type/1 { "title": "This is a document" } PUT my_index/my_type/1 { "title": "This is another document", "body": "This document has a body" } GET my_index/_search { "query": { "terms": { "_field_names": [ "title" ] } }, "aggs": { "Field names": { "terms": { "field": "_field_names", "size": 10 } } }, "script_fields": { "Field names": { "script": "doc['_field_names']" } } }