OpenSearch/docs/reference/query-dsl/queries/template-query.asciidoc

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[[query-dsl-template-query]]
=== Template Query
A query that accepts a query template and a map of key/value pairs to fill in
template parameters.
[source,js]
------------------------------------------
GET /_search
{
"query": {
"template": {
"query": {"match_{{template}}": {}},
"params" : {
"template" : "all"
}
}
}
}
------------------------------------------
Alternatively passing the template as an escaped string works as well:
[source,js]
------------------------------------------
GET /_search
{
"query": {
"template": {
"query": "{\"match_{{template}}\": {}}\"", <1>
"params" : {
"template" : "all"
}
}
}
}
------------------------------------------
<1> New line characters (`\n`) should be escaped as `\\n` or removed,
and quotes (`"`) should be escaped as `\\"`.
You can register a template by storing it in the `config/scripts` directory, in a file using the `.mustache` extension.
In order to execute the stored template, reference it by name in the `query`
parameter:
[source,js]
------------------------------------------
GET /_search
{
"query": {
"template": {
"query": "storedTemplate", <1>
"params" : {
"template" : "all"
}
}
}
}
------------------------------------------
<1> Name of the the query template in `config/scripts/`, i.e., `storedTemplate.mustache`.
Templating is based on Mustache. For simple token substitution all you provide
is a query containing some variable that you want to substitute and the actual
values:
[source,js]
------------------------------------------
GET /_search
{
"query": {
"template": {
"query": {"match_{{template}}": {}},
"params" : {
"template" : "all"
}
}
}
}
------------------------------------------
which is then turned into:
[source,js]
------------------------------------------
{
"query": {
"match_all": {}
}
}
------------------------------------------
You can register a template by storing it in the elasticsearch index `.scripts` or by using the REST API. (See <<search-template>> for more details)
In order to execute the stored template, reference it by name in the `query`
parameter:
[source,js]
------------------------------------------
GET /_search
{
"query": {
"template": {
"query": "templateName", <1>
"params" : {
"template" : "all"
}
}
}
}
------------------------------------------
<1> Name of the the query template stored in the index.
[source,js]
------------------------------------------
GET /_search
{
"query": {
"template": {
"query": "storedTemplate", <1>
"params" : {
"template" : "all"
}
}
}
}
------------------------------------------
There is also a dedicated `template` endpoint, allows you to template an entire search request.
Please see <<search-template>> for more details.