UNLISTEN
SQL - Language Statements
UNLISTEN
Stop listening for notification
1998-10-19
UNLISTEN { notifyname | * }
1998-10-19
Inputs
notifyname
Name of previously registered notify condition.
*
All current listen registrations for this backend are cleared.
1998-10-19
Outputs
UNLISTEN
Acknowledgment that statement has executed.
1998-10-19
Description
UNLISTEN
is used to remove an existing NOTIFY registration.
UNLISTEN cancels any existing registration of the current
Postgres session as a listener on the notify
condition notifyname.
The special condition wildcard "*" cancels all listener registrations
for the current session.
contains a more extensive
discussion of the use of LISTEN and
NOTIFY.
1998-10-19
Notes
classname
need not be a valid class name but can be any string valid
as a name up to 32 characters long.
The backend does not complain if you UNLISTEN something you were not
listening for.
Each backend will automatically execute UNLISTEN * when
exiting.
A restriction in some previous releases of
Postgres that a
classname
which does not correspond to an actual table must be enclosed in double-quotes
is no longer present.
Usage
To subscribe to an existing registration:
LISTEN virtual;
LISTEN
NOTIFY virtual;
NOTIFY
Asynchronous NOTIFY 'virtual' from backend with pid '8448' received
Once UNLISTEN has been executed, further NOTIFY commands will be
ignored:
UNLISTEN virtual;
UNLISTEN
NOTIFY virtual;
NOTIFY
-- notice no NOTIFY event is received
Compatibility
1998-10-19
SQL92
There is no UNLISTEN in SQL92.