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Sql
Sql.pgsql
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Method Sql.pgsql()->set_notify_callback()
- Method
set_notify_callback
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void set_notify_callback(string condition, void|function(int:void) notify_cb, void|int selfnotify, mixed ... args)
- Description
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With PostgreSQL you can LISTEN to NOTIFY events.
This function allows you to detect and handle such events.
- Parameter condition
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Name of the notification event we're listening
to. A special case is the empty string, which matches all events,
and can be used as fallback function which is called only when the
specific condition is not handled. Another special case is
_reconnect which gets called whenever the connection unexpectedly
drops and reconnects to the database.
- Parameter notify_cb
-
Function to be called on receiving a notification-event of
condition condition .
The callback function is invoked with
void notify_cb(pid,condition,extrainfo, .. args);
pid is the process id of the database session that originated
the event. condition contains the current condition.
extrainfo contains optional extra information specified by
the database.
The rest of the arguments to notify_cb are passed
verbatim from args .
The callback function must return no value.
- Parameter selfnotify
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Normally notify events generated by your own session are ignored.
If you want to receive those as well, set selfnotify to one.
- Parameter args
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Extra arguments to pass to notify_cb .
- Note
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This function is PostgreSQL-specific, and thus it is not available
through the generic SQL-interface.
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