NAME
UNLISTEN - 停止监听通知信息
SYNOPSIS
UNLISTEN { name | * }
DESCRIPTION 描述
UNLISTEN 用于删除一个现有的已注册的 NOTIFY 事件。 UNLISTEN 取消当前 PostgreSQL 会话中的所有对通知条件 notifyname 监听。 特殊的条件通配符 * 则取消对当前会话的所有通知条件的监听。
NOTIFY [notify(7)] 包含一些对 LISTEN 和 NOTIFY 的使用的更广泛的讨论。
PARAMETERS 参数
- name
通知条件名称（任意标识符）。- *
所有此后端当前正在监听的注册都将被清除。
NOTES 注意
如果你 UNLISTEN 一个你没有监听的事件，后端不会报错。
每个后端在退出时都会自动执行 UNLISTEN *。
EXAMPLES 例子
注册一个：
LISTEN virtual; NOTIFY virtual; Asynchronous notification "virtual" received from server process with PID 8448.
一旦执行了 UNLISTEN，以后的 NOTIFY 命令将被忽略：
UNLISTEN virtual; NOTIFY virtual; -- no NOTIFY event is received
COMPATIBILITY 兼容性
SQL 标准里没有 UNLISTEN。
SEE ALSO 参见
LISTEN [listen(7)], NOTIFY [notify(l)]
#p#
NAME
UNLISTEN - stop listening for a notification
SYNOPSIS
UNLISTEN { name | * }
DESCRIPTION
UNLISTEN is used to remove an existing registration for NOTIFY events. UNLISTEN cancels any existing registration of the current PostgreSQL session as a listener on the notification name. The special wildcard * cancels all listener registrations for the current session.
NOTIFY [notify(7)] contains a more extensive discussion of the use of LISTEN and NOTIFY.
PARAMETERS
- name
- Name of a notification (any identifier).
- *
- All current listen registrations for this session are cleared.
NOTES
You may unlisten something you were not listening for; no warning or error will appear.
At the end of each session, UNLISTEN * is automatically executed.
EXAMPLES
To make a registration:
LISTEN virtual; NOTIFY virtual; Asynchronous notification "virtual" received from server process with PID 8448.
Once UNLISTEN has been executed, further NOTIFY commands will be ignored:
UNLISTEN virtual; NOTIFY virtual; -- no NOTIFY event is received
COMPATIBILITY
There is no UNLISTEN command in the SQL standard.
SEE ALSO
LISTEN [listen(7)], NOTIFY [notify(l)]
