如何在Esper中获取基础事件

Question

I have created a listener implementing UpdateListener interface, which is attached to an Event (Example - TestEvent). Now every time this event is raised, I want to get the underlying event for TestEvent and print that.

Example:

Statement 1 -

on ParentEvent1 insert into TestEvent

Statement 2 -

on ParentEvent2 insert into TestEvent

Statement 3 -

on ParentEvent3 insert into TestEvent

Statement 4 -

on ParentEvent4 insert into TestEvent

So whenever TestEvent is raised, I need to print "TestEvent is raised because of ParentEvent4","TestEvent is raised because of ParentEvent1" etc.

Thanks, Regards, Ankit Jain

Answer 1

This is done by selecting some information regarding the triggering event itself from the stream.

on ParentEvent1 as p1 insert into TestEvent select p1, somemoreinformation from MyNamedWindow

Instead of selecting the event itself its also fine to select some text:

on P1 insert into TestEvent select 'P1' as triggeredBy from ...
on P2 insert into TestEvent select 'P2' as triggeredBy from ...