Session: Querying: How to Perform a Faceted (Aggregated) Search
To execute facet (aggregation) query using the session query()
method, use the aggregateBy()
or aggregateUsing()
methods. This will scope you to the aggregation query builder where you will be allowed to define single or multiple facets for the query using a straightforward and fluent API.
Syntax
query.aggregateBy(facetBuilder);
query.aggregateBy(facet);
query.aggregateBy(...facets);
query.aggregateUsing(facetSetupDocumentId);
Parameters | |||
---|---|---|---|
facet | FacetBase |
FacetBase implementation defining the scope of the facet and its options (either Facet or RangeFacet ) |
|
facets | ...FacetBase |
Items containing FacetBase implementations |
|
facetBuilder | (builder) => void |
Builder with a fluent API that constructs a FacetBase instance |
|
facetSetupDocumentId | string | ID of a document containing FacetSetup |
Facet & RangeFacet
Facet vs RangeFacet
RangeFacet
allows you to split the results of the calculations into several ranges, in contrast to Facet
where whole spectrum of results will be used to generate a single outcome.
FacetAggregation
is one of the following:
-
"None"
-
"Max"
-
"Min"
-
"Average"
-
"Sum"
Facet
Fields | |
---|---|
fieldName | string |
options | FacetOptions |
aggregrations | Map<FieldAggregration, string> |
displayFieldName | string |
RangeFacet
Fields | |
---|---|
ranges | string[] |
options | FacetOptions |
aggregrations | Map<FieldAggregration, string> |
displayFieldName | string |
Builder
facetBuilder.byRanges(range, ...ranges);
facetBuilder.byField(fieldName);
facetBuilder.withDisplayName(displayName);
facetBuilder.withOptions(options);
facetBuilder.sumOn(path);
facetBuilder.minOn(path);
facetBuilder.maxOn(path);
facetBuilder.averageOn(path);
Parameters | ||
---|---|---|
path | string | Points to the index field that should be used for operation (byRanges() , byField() ) or to document field that should be used for aggregation (sumOn() , minOn() , maxOn() , averageOn() ) |
fieldName | string | Points to the index field that should be used for operation (byRanges() , byField() ) or to document field that should be used for aggregation (sumOn() , minOn() , maxOn() , averageOn() ) |
displayName | string | If set, results of a facet will be returned under this name |
options | object | Non-default options that should be used for operation |
termSortMode | string | Indicates how terms should be sorted (ValueAsc , ValueDesc , CountAsc , CountDesc ) |
includeRemainingTerms | boolean | Indicates if remaining terms should be included in results |
start | number | Used to skip given number of facet results in the outcome |
pageSize | number | Used to limit facet results to the given value |
Example I
const facetOptions = {
termSortMode: "CountDesc"
};
const facet1 = new Facet();
facet1.fieldName = "manufacturer";
facet1.options = facetOptions;
const facet2 = new RangeFacet();
facet2.ranges = [
"cost < 200",
"cost between 200 and 400",
"cost between 400 and 600",
"cost between 600 and 800",
"cost >= 800"
];
facet2.aggregations = new Map([["Average", "cost"]]);
const facet3 = new RangeFacet();
facet3.ranges = [
"megapixels < 3",
"megapixels between 3 and 7",
"megapixels between 7 and 10",
"megapixels >= 10"
];
const facets = await session
.query({ indexName: "Camera/Costs" })
.aggregateBy(facet1)
.andAggregateBy(facet2)
.andAggregateBy(facet3)
.execute();
from index 'Camera/Costs'
select
facet(manufacturer),
facet(cost < 200, cost >= 200 AND cost < 400, cost >= 400 AND cost < 600, cost >= 600 AND cost < 800, cost >= 800),
facet(megapixels < 3, megapixels >= 3 AND megapixels < 7, megapixels >= 7 AND megapixels < 10, megapixels >= 10)
Example II
const options = { termSortMode: "CountDesc" };
const costBuilder = RangeBuilder.forPath("cost");
const megapixelsBuilder = RangeBuilder.forPath("megapixels");
const facetResult = await session
.query({ indexName: "Camera/Costs" })
.aggregateBy(builder => builder
.byField("manufacturer")
.withOptions(options))
.andAggregateBy(builder => builder
.byRanges(
costBuilder.isLessThan(200),
costBuilder.isGreaterThanOrEqualTo(200).isLessThan(400),
costBuilder.isGreaterThanOrEqualTo(400).isLessThan(600),
costBuilder.isGreaterThanOrEqualTo(600).isLessThan(800),
costBuilder.isGreaterThanOrEqualTo(800))
.averageOn("cost"))
.andAggregateBy(builder => builder
.byRanges(
megapixelsBuilder.isLessThan(3),
megapixelsBuilder.isGreaterThanOrEqualTo(3).isLessThan(7),
megapixelsBuilder.isGreaterThanOrEqualTo(7).isLessThan(10),
megapixelsBuilder.isGreaterThanOrEqualTo(10)
))
.execute();
from index 'Camera/Costs'
select
facet(manufacturer),
facet(cost < 200, cost >= 200 and cost < 400, cost >= 400 and cost < 600, cost >= 600 and cost < 800, cost >= 800),
facet(megapixels < 3, megapixels >= 3 AND megapixels < 7, megapixels >= 7 AND megapixels < 10, megapixels >= 10)
Example III
const facetSetup = new FacetSetup();
const facetManufacturer = new Facet();
facetManufacturer.fieldName = "manufacturer";
facetSetup.facets = [ facetManufacturer ];
const cameraFacet = new RangeFacet();
cameraFacet.ranges = [
"cost < 200",
"cost between 200 and 400",
"cost between 400 and 600",
"cost between 600 and 800",
"cost >= 800"
];
const megapixelsFacet = new RangeFacet();
megapixelsFacet.ranges = [
"megapixels < 3",
"megapixels between 3 and 7",
"megapixels between 7 and 10",
"megapixels >= 10"
];
facetSetup.rangeFacets = [ cameraFacet, megapixelsFacet ];
await session.store(facetSetup, "facets/CameraFacets");
await session.saveChanges();
const facets = await session
.query({ indexName: "Camera/Costs" })
.aggregateUsing("facets/CameraFacets")
.execute();
from index 'Camera/Costs'
select facet(id('facets/CameraFacets'))
Remarks
Warning
aggregateBy()
only supports aggregation by a single field. If you want to aggregate by multiple fields, you need to emit a single field that contains all values.