Object - streams : Select

The Select object represents the select clause. Anything that comes under select clause like aggregator function invocations are also handled in this processor. Further, grouping of the events (provided by the groupby clause) is also performed in this processor. aggregatorArr is an array of aggregators which are used in the select clause. groupbyFuncArray is an array of function pointers which returns the values being grouped. selectFunc is a function pointer to a lambda function which creates the data field of the output stream event. scopeName is used as a breadcrumb to identify the select clause if there are multiple forever blocks.

process

Selects only the selected fields in the select clause.

Parameters

  • streamEvents StreamEvent?[]
  • The array of stream events passed to the select clause.

getGroupByKey

( function(StreamEvent) returns (anydata) []? groupbyFunctionArray, StreamEvent e)

returns string

Creates a unique key for each group with the given values in the group by clause.

Parameters

  • groupbyFunctionArray function(StreamEvent) returns (anydata) []?
  • Function pointer array to the lambda function which returns each group by field.

  • Return Type

    (string)
  • Returns a unique groupby key by which the event e is grouped.