An event expression is a special type of expression that is used with the
on statement (see
The on statement) to define the rules for detecting events of interest and invoking an action when a matching event is detected. In an event expression, you can specify filtering rules based on an event’s field values, sequencing rules for events followed by other events, times and time ranges during which an event is of interest, and other rules.
Event expressions should not be confused with ordinary EPL expressions of type
event. Ordinary EPL expressions of all types are described in
Expressions.
The
on statement is discussed in
The on statement, but because the
on statement and event expressions are so closely related, here are the
on statement diagrams:
