Adding query actions
In a query definition, you specify the actions you want Apama to perform when it finds a match for the event pattern specified in the query. You can add one or more actions and there are three kinds of actions that you can add:
Send event actions send an event to a channel that you specify.
Custom EPL actions can do anything that can be defined in an EPL action.
Route event actions route events to a channel that you specify.
Note:
It is recommended to use the Route event action rather than Send event when events are being sent from one query to another. This is important when using reliable messaging, since although an external event will not be acknowledged until all routed events arising from it have been processed, the acknowledgement will not wait for any sent events to be processed.
Before you define query actions, you should add the query input events and specify the query pattern. If this is a parameterized query, you should add the query parameters before you add actions. You can then refer to the parameters in the actions.
You add query actions in the
Actions pane of the
Design view. Click the down arrow to the right of the plus sign
and select the kind of action you want to add. Query Designer displays a dialog where you define the action.
After you add an action in the Design view, its name appears in a row in the Actions pane. Select the action name to edit or delete it.
When you add an action, it is immediately added to the source code. Any changes you make in the Source tab will be shown in the Design tab, and vice versa. If you introduce any errors into the query source code then you must resolve them in the Source tab before you can view the query in the Design tab.
For more details about the EPL code for query actions, see
Acting on pattern matches. See also:
Specifying actions in event definitions.