Postgresql 中文操作指南

dblink_get_notify

dblink_get_notify — 检索连接上的异步通知

dblink_get_notify — retrieve async notifications on a connection

Synopsis

dblink_get_notify() returns setof (notify_name text, be_pid int, extra text)
dblink_get_notify(text connname) returns setof (notify_name text, be_pid int, extra text)

Description

dblink_get_notify 在未命名连接上或在指定命名连接上检索通知。要通过 dblink 接收通知，首先必须使用 dblink_exec 发出 LISTEN 。如需详情，请参阅 LISTEN 和 NOTIFY 。

dblink_get_notify retrieves notifications on either the unnamed connection, or on a named connection if specified. To receive notifications via dblink, LISTEN must first be issued, using dblink_exec. For details see LISTEN and NOTIFY.

Arguments

  • connname

    • The name of a named connection to get notifications on.

Return Value

返回 setof (notify_name text, be_pid int, extra text) ，如果没有则返回一个空集。

Returns setof (notify_name text, be_pid int, extra text), or an empty set if none.

Examples

SELECT dblink_exec('LISTEN virtual');
 dblink_exec
-------------
 LISTEN
(1 row)

SELECT * FROM dblink_get_notify();
 notify_name | be_pid | extra
-------------+--------+-------
(0 rows)

NOTIFY virtual;
NOTIFY

SELECT * FROM dblink_get_notify();
 notify_name | be_pid | extra
-------------+--------+-------
 virtual     |   1229 |
(1 row)