107 lines
3.2 KiB
Plaintext
107 lines
3.2 KiB
Plaintext
[[query-dsl-has-parent-query]]
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=== Has parent query
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++++
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<titleabbrev>Has parent</titleabbrev>
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++++
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The `has_parent` query accepts a query and a parent type. The query is
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executed in the parent document space, which is specified by the parent
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type. This query returns child documents which associated parents have
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matched. For the rest `has_parent` query has the same options and works
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in the same manner as the `has_child` query.
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[source,js]
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--------------------------------------------------
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GET /_search
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{
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"query": {
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"has_parent" : {
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"parent_type" : "blog",
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"query" : {
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"term" : {
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"tag" : "something"
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}
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}
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}
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}
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}
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--------------------------------------------------
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// CONSOLE
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Note that the `has_parent` is a slow query compared to other queries in the
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query dsl due to the fact that it performs a join. The performance degrades
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as the number of matching parent documents increases. If you care about query
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performance you should not use this query. However if you do happen to use
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this query then use it as less as possible. Each `has_parent` query that gets
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added to a search request can increase query time significantly.
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[float]
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==== Scoring capabilities
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The `has_parent` also has scoring support. The default is `false` which
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ignores the score from the parent document. The score is in this
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case equal to the boost on the `has_parent` query (Defaults to 1). If
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the score is set to `true`, then the score of the matching parent
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document is aggregated into the child documents belonging to the
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matching parent document. The score mode can be specified with the
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`score` field inside the `has_parent` query:
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[source,js]
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--------------------------------------------------
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GET /_search
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{
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"query": {
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"has_parent" : {
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"parent_type" : "blog",
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"score" : true,
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"query" : {
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"term" : {
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"tag" : "something"
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}
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}
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}
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}
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}
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--------------------------------------------------
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// CONSOLE
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[float]
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==== Ignore Unmapped
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When set to `true` the `ignore_unmapped` option will ignore an unmapped `type`
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and will not match any documents for this query. This can be useful when
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querying multiple indexes which might have different mappings. When set to
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`false` (the default value) the query will throw an exception if the `type`
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is not mapped.
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[float]
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==== Sorting
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Child documents can't be sorted by fields in matching parent documents via the
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regular sort options. If you need to sort child documents by field in the parent
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documents then you should use the `function_score` query and then just sort
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by `_score`.
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Sorting tags by parent document' `view_count` field:
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[source,js]
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--------------------------------------------------
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GET /_search
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{
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"query": {
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"has_parent" : {
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"parent_type" : "blog",
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"score" : true,
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"query" : {
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"function_score" : {
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"script_score": {
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"script": "_score * doc['view_count'].value"
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}
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}
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}
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}
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}
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}
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--------------------------------------------------
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// CONSOLE
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