MySQL事件调度器_MySQL
bitsCN.com
MySQL 5.1 中新增了事件调度器这一个功能。可以实现类似于SQL Server的Job功能。
1.语法:


CREATE EVENT [IF NOT EXISTS] event_nameON SCHEDULE schedule [ON COMPLETION [NOT] PRESERVE][ENABLE | DISABLE][COMMENT 'comment']DO sql_statement;
其中schedule的语句可以表示为:


AT TIMESTAMP [+ INTERVAL]| EVERY INTERVAL [STARTS TIMESTAMP] [ENDS TIMESTAMP]
interval的单位可以有如下几种:


YEAR | QUARTER | MONTH | DAY | HOUR | MINUTE |WEEK | SECOND | YEAR_MONTH | DAY_HOUR | DAY_MINUTE | DAY_SECOND | HOUR_MINUTE | HOUR_SECOND | MINUTE_SECOND
2.开启、关闭事件调度器:
在使用这个功能之前必须确保event_scheduler已开启.


/*开启*/SET GLOBAL event_scheduler = 1;-- 或SET GLOBAL event_scheduler = ON;/*关闭*/SET GLOBAL event_scheduler = 0;-- 或SET GLOBAL event_scheduler = OFF;
3.示例:
创建测试数据库:


CREATE TABLE tst_event (createtime DATETIME);
创建测试用存储过程:


/*创建测试用存储过程*/CREATE PROCEDURE msp_TestEvent()BEGIN INSERT INTO tst_event VALUES (CURRENT_TIMESTAMP);END
创建事件调度器:


CREATE EVENT IF NOT EXISTS me_TestEvent ON SCHEDULE EVERY 10 SECOND STARTS '2014-02-28 16:45:00' ENDS DATE_ADD('2014-02-28 16:46:00',INTERVAL 1 SECOND) DO CALL msp_TestEvent();
修改事件调度器:


/*修改EVENT*/ ALTER EVENT me_TestEvent ON SCHEDULE EVERY 10 SECOND STARTS '2014-02-27 16:45:00' ENDS DATE_ADD('2014-02-27 16:46:00',INTERVAL 1 SECOND) DO INSERT INTO tst_event VALUES (CURRENT_TIMESTAMP);
查看事件调度器:


/*查看EVENT*/ show events;-- 或select * from information_schema.events
4.不同时间间隔的调度:
一天后执行调度器:


/*一天后执行调度器T*/ CREATE EVENT e_TestEventON SCHEDULE AT CURRENT_TIMESTAMP + INTERVAL 1 DAYDO CALL msp_TestEvent();
2014-02-28日执行调度器:


/*2014-02-28日执行调度器*/ CREATE EVENT e_TestEventON SCHEDULE AT TIMESTAMP '2014-02-28 00:00:00'DO CALL msp_TestEvent();
每天执行调度器:


/*每天执行调度器*/ CREATE EVENT e_TestEventON SCHEDULE EVERY 1 DAYDO CALL msp_TestEvent();
一天后每天执行调度器:


/*一天后每天执行调度器*/ CREATE EVENT e_TestEventON SCHEDULE EVERY 1 DAYSTARTS CURRENT_TIMESTAMP + INTERVAL 2 DAYDO CALL msp_TestEvent();
每天执行调度器,10天后停止:


/*每天执行调度器,10天后停止*/ CREATE EVENT e_TestEventON SCHEDULE EVERY 1 DAYENDS CURRENT_TIMESTAMP + INTERVAL 10 DAYDO CALL msp_TestEvent();
一天后开始,每天执行调度器,10天后停止:


/*一天后开始,每天执行调度器,10天后停止*/ CREATE EVENT e_TestEventON SCHEDULE EVERY 1 DAYSTARTS CURRENT_TIMESTAMP + INTERVAL 1 DAYENDS CURRENT_TIMESTAMP + INTERVAL 10 MONTHDO CALL msp_TestEvent();
每天执行调度器,只执行一次:


/*每天执行调度器,只执行一次*/ CREATE EVENT e_TestEventON SCHEDULE EVERY 1 DAYON COMPLETION NOT PRESERVEDO CALL msp_TestEvent();
5.删除调度器:


DROP EVENT [IF EXISTS] event_name

Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

AI Hentai Generator
Generate AI Hentai for free.

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Hot Topics



InnoDB's full-text search capabilities are very powerful, which can significantly improve database query efficiency and ability to process large amounts of text data. 1) InnoDB implements full-text search through inverted indexing, supporting basic and advanced search queries. 2) Use MATCH and AGAINST keywords to search, support Boolean mode and phrase search. 3) Optimization methods include using word segmentation technology, periodic rebuilding of indexes and adjusting cache size to improve performance and accuracy.

The article discusses using MySQL's ALTER TABLE statement to modify tables, including adding/dropping columns, renaming tables/columns, and changing column data types.

Full table scanning may be faster in MySQL than using indexes. Specific cases include: 1) the data volume is small; 2) when the query returns a large amount of data; 3) when the index column is not highly selective; 4) when the complex query. By analyzing query plans, optimizing indexes, avoiding over-index and regularly maintaining tables, you can make the best choices in practical applications.

Yes, MySQL can be installed on Windows 7, and although Microsoft has stopped supporting Windows 7, MySQL is still compatible with it. However, the following points should be noted during the installation process: Download the MySQL installer for Windows. Select the appropriate version of MySQL (community or enterprise). Select the appropriate installation directory and character set during the installation process. Set the root user password and keep it properly. Connect to the database for testing. Note the compatibility and security issues on Windows 7, and it is recommended to upgrade to a supported operating system.

The difference between clustered index and non-clustered index is: 1. Clustered index stores data rows in the index structure, which is suitable for querying by primary key and range. 2. The non-clustered index stores index key values and pointers to data rows, and is suitable for non-primary key column queries.

Article discusses popular MySQL GUI tools like MySQL Workbench and phpMyAdmin, comparing their features and suitability for beginners and advanced users.[159 characters]

Article discusses strategies for handling large datasets in MySQL, including partitioning, sharding, indexing, and query optimization.

The article discusses dropping tables in MySQL using the DROP TABLE statement, emphasizing precautions and risks. It highlights that the action is irreversible without backups, detailing recovery methods and potential production environment hazards.
