Package net.pricefx.formulaengine.scripting.queryapi

Interface Groups

All Known Subinterfaces:
Groups.GroupingSetsBuilder
public interface Groups
List of grouping builder to be used in PipelineStage.aggregateByGroups(Function, Function)

A grouping is a set of columns to aggregate on. With several groupings, one aggregation stage computes the aggregates for each grouping, instead of one pipeline per grouping combined with a union.

Get an instance with QueryApi.groups(), that is api.queryApi().groups(). Define the groupings with groupingSets(List[]), cube(List[]) or rollup(List[]), and end the specification with Groups.GroupingSetsBuilder.distinct() or Groups.GroupingSetsBuilder.notDistinct().

For example, this pipeline computes the price sum by customerGroup and productGroup, by customerGroup only, and over all rows: 


 def qapi = api.queryApi()
 def dm = qapi.tables().datamart("Sales")

 qapi.source(dm, [dm.customerGroup, dm.productGroup, dm.price])
     .aggregateByGroups(
         { prev -> qapi.groups().rollup([prev.customerGroup, prev.productGroup]).notDistinct() },
         { prev -> [prev.customerGroup, prev.productGroup, qapi.exprs().sum(prev.price).as("priceSum")] }
     )
     .stream { it.toList() }
See Also:

  • Method Details

    • cube

      Groups.GroupingSetsBuilder cube(List<Expression>... groups)
      Builds the cube list of grouping from a given list of expressions or sub lists of expressions.

      It results to the given list plus all of its possible subsets (i.e. the power set).

      For example, 

      
 qapi.groups().cube([a, b, c])
 // is equivalent to
 qapi.groups().groupingSets(
   [a, b, c],
   [a, b],
   [a, c],
   [a],
   [b, c],
   [b],
   [c],
   []
 )
      If you provide several lists, then the cube will be computed over the lists

      For example, 

      
 qapi.groups().cube([a, b], [c, d])
 // is equivalent to
 qapi.groups().groupingSets(
   [a, b, c , d],
   [a, b],
   [c, d],
   []
 )
      Parameters:
      groups - list of column groups to cube over; must not be null or empty, and no group may be empty
      Returns:
      the current groups builder
      Since:
      16.3.12 - Black Cat, 17.0.3 - Paloma
      See Also:

    • rollup

      Groups.GroupingSetsBuilder rollup(List<Expression>... groups)
      Builds the rollup grouping list from a given list of expressions or sub lists of expressions.

      It results to the given list of expressions and all prefixes of the list including the empty list. For example, 

      
 qapi.groups().rollup([a, b, c])
 // is equivalent to
 qapi.groups().groupingSets(
   [a, b, c],
   [a, b],
   [a],
   []
 )
      If you provide several lists, then the rollup will be computed over the lists

      For example, 

      
 qapi.groups().rollup([a], [b, c], [d])
 // is equivalent to
 qapi.groups().groupingSets(
   [a, b, c , d],
   [a, b, c],
   [a],
   []
 )
      Parameters:
      groups - list of column groups to roll up; must not be null or empty, and no group may be empty
      Returns:
      the current groups builder
      Since:
      16.3.12 - Black Cat, 17.0.3 - Paloma
      See Also:

    • groupingSets

      Groups.GroupingSetsBuilder groupingSets(List<Expression>... groups)
      Builds a representation of a list of grouping to aggregate on.

      Each sublist of groupingSets may specify zero or more expressions and is interpreted the same way as though it were directly in a PipelineStage.aggregateBy(Function, Function) stage.

      An empty grouping set means that all rows are aggregated down to a single group.

      For example, this by function of PipelineStage.aggregateByGroups(Function, Function) aggregates by customerGroup and productGroup, by productGroup only, and over all rows: 

      
 { prev ->
     qapi.groups()
         .groupingSets([prev.customerGroup, prev.productGroup], [prev.productGroup], [])
         .notDistinct()
 }
      Parameters:
      groups - explicit list of grouping sets; must not be null or empty
      Returns:
      a builder to choose Groups.GroupingSetsBuilder.distinct() or Groups.GroupingSetsBuilder.notDistinct()
      Since:
      16.3.12 - Black Cat, 17.0.3 - Paloma
      See Also: