NEsper/Esper EPL event statement

Question

Can anyone help me define the EPL statement to catch the event when the following situation occurs:

Assumming that there are events with 3 attributes - (string)Symbol, (boolean)Value, (datetime)Timestamp.

If the events have the same Symbol and have Value both true and false at the same time, should be captured. For example event1(Symbol - apple, Value - True, Timestamp - 20210614-14:00:00) and event2(Symbol - apple, Value - False, Timestamp - 20210614-14:00:00). But if the events have different Symbols (like apple and banana) should be ignored (not captured).

Thanks for any help.

Narsu

Events (symbol, value, timestamp) with same timestamp and symbol and different value (true and false) should be captured. — Narsu, Jun 14 '21 at 11:59

score 0 · Answer 1 · answered Jun 14 '21 at 20:55

This would match two events immediately following each other (no criteria were stated as to what can come in between)

select * from MyEvent
  match_recognize (
    partition by symbol
    measures a, b
    pattern (a b)
    define
      b as b.timestamp = a.timestamp and b.value != a.value
)

NEsper/Esper EPL event statement

1 Answers1