DROP EVENT

Description

Deletes a scheduled task.

Precautions

Operations related to scheduled tasks are supported only when sql_compatibility is set to 'B'.

Syntax

DROP EVENT [IF EXISTS] event_name;

Parameters

IF EXISTS
If the scheduled task does not exist, a NOTICE message is displayed.

Examples

-- Create and switch to the test database.
gaussdb=# CREATE DATABASE test_event WITH DBCOMPATIBILITY = 'b';
gaussdb=# \c test_event

-- Create a table.
test_event=# CREATE TABLE t_ev(num int);

-- Create a scheduled event that is executed once every five seconds. After the event is executed, the scheduled event is automatically deleted.
test_event=# CREATE EVENT IF NOT EXISTS event_e1 ON SCHEDULE AT sysdate + interval 5 second DO INSERT INTO t_ev VALUES(0);

-- Query the table five seconds later.
test_event=# SELECT * FROM t_ev;
 num 
-----
   0
(1 row)

-- Create a scheduled event that is executed every minute.
test_event=# CREATE EVENT IF NOT EXISTS event_e2 ON SCHEDULE EVERY 1 minute DO INSERT INTO t_ev VALUES(1);

-- Query the table every one minute. A new record is displayed.
test_event=# SELECT * FROM t_ev;
 num 
-----
   0
   1
   1
(3 rows)

-- Delete the scheduled event.
test_event=# DROP EVENT event_e2;

-- Drop the table.
test_event=# DROP TABLE t_ev;

-- Switch back to the initial database and delete the test database. Replace postgres with the actual database name.
test_event=#\c postgres
gaussdb=# DROP DATABASE test_event;