[[query-dsl-parent-id-query]]
=== Parent Id Query

added[5.0.0]

The `parent_id` query can be used to find child documents which belong to a particular parent:

[source,js]
--------------------------------------------------
{
    "parent_id" : {
        "type" : "blog_tag",
        "id" : "1"
    }
}
--------------------------------------------------

The above is functionally equivalent to using the following
<<query-dsl-has-parent-query, `has_parent`>> query, but performs
better as it does not need to do a join:

[source,js]
--------------------------------------------------
{
  "has_parent": {
    "type": "blog",
    "query": {
      "term": {
        "_id": "1"
      }
    }
  }
}
--------------------------------------------------

==== Parameters

This query has two required parameters:

[horizontal]
`type`::  The **child** type. This must be a type with `_parent` field.

`id`::    The required parent id select documents must referrer to.

`ignore_unmapped`::  When set to `true` this will ignore an unmapped `type` and will not match any 
documents for this query. This can be useful when querying multiple indexes
which might have different mappings. When set to `false` (the default value)
the query will throw an exception if the `type` is not mapped.