Session: Querying: How to perform dynamic aggregation?

Dynamic aggregation can be performed using aggregateBy method. Internally such aggregation is an extended faceted search.

Syntax

public DynamicAggregationQuery<T> aggregateBy(String path);

public DynamicAggregationQuery<T> aggregateBy(String path, String displayName);

public DynamicAggregationQuery<T> aggregateBy(Path<?> path);

public DynamicAggregationQuery<T> aggregateBy(Path<?> path, String displayName);

Example I - summing

// sum up all order prices
// for each customer
// where price is higher than 500
QHowToPerformDynamicAggregation_Order o = QHowToPerformDynamicAggregation_Order.order;
FacetResults aggregationResults = session
  .query(Order.class, "Orders/All")
  .where(o.totalPrice.gt(500))
  .aggregateBy(o.customerId)
    .sumOn(o.totalPrice)
  .toList();

FacetResult customerAggregation = aggregationResults.getResults().get("CustomerId");
Double sum = customerAggregation.getValues().get(0).getSum();

Example II - counting

// count all orders
// for each customer
// where price is higher than 500
QHowToPerformDynamicAggregation_Order o = QHowToPerformDynamicAggregation_Order.order;
FacetResults aggregationResults = session
  .query(Order.class, "Orders/All")
  .where(o.totalPrice.gt(500))
  .aggregateBy(o.customerId)
    .countOn(o.totalPrice)
  .toList();

FacetResult customerAggregation = aggregationResults.getResults().get("CustomerId");
Integer count = customerAggregation.getValues().get(0).getCount();

Example III - average

// count price average for orders
// for each customer
// where price is higher than 500
QHowToPerformDynamicAggregation_Order o = QHowToPerformDynamicAggregation_Order.order;
FacetResults aggregationResults = session
  .query(Order.class, "Orders/All")
  .where(o.totalPrice.gt(500))
  .aggregateBy(o.customerId)
    .averageOn(o.totalPrice)
  .toList();

FacetResult customerAggregation = aggregationResults.getResults().get("CustomerId");
Double average = customerAggregation.getValues().get(0).getAverage();

Example IV - maximum and minimum

// count max and min price for orders
// for each customer
// where price is higher than 500
QHowToPerformDynamicAggregation_Order o = QHowToPerformDynamicAggregation_Order.order;
FacetResults aggregationResults = session
  .query(Order.class, "Orders/All")
  .where(o.totalPrice.gt(500))
  .aggregateBy(o.customerId)
    .minOn(o.totalPrice)
    .maxOn(o.totalPrice)
  .toList();

FacetResult customerAggregation = aggregationResults.getResults().get("CustomerId");
Double min = customerAggregation.getValues().get(0).getMin();
Double max = customerAggregation.getValues().get(0).getMax();

Example V - adding ranges

QHowToPerformDynamicAggregation_Order o = QHowToPerformDynamicAggregation_Order.order;
FacetResults aggregationResults = session.query(Order.class, "Orders/All")
  .aggregateBy(o.customerId)
    .addRanges(o.totalPrice.lt(10))
    .addRanges(o.totalPrice.goe(100).and(o.totalPrice.lt(500)))
    .addRanges(o.totalPrice.goe(500).and(o.totalPrice.lt(1000)))
    .addRanges(o.totalPrice.goe(1000))
  .toList();

FacetResult customerAggregation = aggregationResults.getResults().get("CustomerId");
List<FacetValue> values = customerAggregation.getValues();

Example VI - multiple aggregations

// sum up all order prices
// for each customer
// count price average for all orders
// for each company
QHowToPerformDynamicAggregation_Order o = QHowToPerformDynamicAggregation_Order.order;
FacetResults aggregationResults = session
  .query(Order.class, "Orders/All")
  .aggregateBy(o.customerId)
    .sumOn(o.totalPrice)
  .andAggregateOn(o.companyId)
    .averageOn(o.totalPrice)
  .toList();

FacetResult customerAggregation = aggregationResults.getResults().get("CustomerId");
FacetResult companyAggregation = aggregationResults.getResults().get("CompanyId");

Double sum = customerAggregation.getValues().get(0).getSum();
Double average = companyAggregation.getValues().get(0).getAverage();