Returns parent documents whose joined child documents match a provided query. You can create parent-child relationships between documents in the same index using a join field mapping.

Because it performs a join, the has_child is slow compared to other queries. Its performance degrades as the number of matching child documents pointing to unique parent documents increases. Each has_child query in a search can increase query time significantly.

If you care about query performance, do not use this query. If you need to use the has_child query, use it as rarely as possible.

(Required, query object) Query you wish to run on child documents of the type field. If a child document matches the search, the query returns the parent document. ignore_unmapped

(Optional, Boolean) Indicates whether to ignore an unmapped type and not return any documents instead of an error. Defaults to false .

If false , Elasticsearch returns an error if the type is unmapped.

You can use this parameter to query multiple indices that may not contain the type .

max_children (Optional, integer) Maximum number of child documents that match the query allowed for a returned parent document. If the parent document exceeds this limit, it is excluded from the search results. min_children (Optional, integer) Minimum number of child documents that match the query required to match the query for a returned parent document. If the parent document does not meet this limit, it is excluded from the search results. score_mode

(Optional, string) Indicates how scores for matching child documents affect the root parent document’s relevance score . Valid values

You cannot sort the results of a has_child query using standard sort options .

If you need to sort returned documents by a field in their child documents, use a function_score query and sort by _score . For example, the following query sorts returned documents by the click_count field of their child documents.

GET /_search
  "query": {
    "has_child": {
      "type": "child",
      "query": {
        "function_score": {
          "script_score": {
            "script": "_score * doc['click_count'].value"
      "score_mode": "max"