EVENT INIT

From InterBase

Go Up to Statement and Function Reference (Language Reference Guide)


Registers interest in one or more events with the InterBase event manager. Available in gpre.

EVENT INIT request_name [dbhandle] 
[('string' | :variable [, 'string' | :variable ]);
Argument Description

<request_name>

Application event handle

<dbhandle>

Specifies the database to examine for occurrences of the events; if omitted, <dbhandle> defaults to the database named in the most recent SET DATABASE statement.

‘<string>’

Unique name identifying an event associated with <event_name>.

<variable>

Host-language character array containing a list of event names to associate with.

Description: EVENT INIT is the first step in the InterBase two-part synchronous event ­mechanism:

  1. EVENT INIT registers an application interest in an event.
  2. EVENT WAIT causes the application to wait until notified of the event occurrence.

EVENT INIT registers an application interest in a list of events in parentheses. The list should correspond to events posted by stored procedures or triggers in the database. If an application registers interest in multiple events with a single EVENT INIT, then when one of those events occurs, the application must determine which event occurred.

Events are posted by a POST_EVENT call within a stored procedure or trigger.

The event manager keeps track of events of interest. At commit time, when an event occurs, the event manager notifies interested applications.

Example: The following embedded SQL statement registers interest in an event:

EXEC SQL
EVENT INIT ORDER_WAIT EMPDB ('new_order');

See Also

Advance To: