Home Database Mysql Tutorial 创建MySQL触发器的语法介绍

创建MySQL触发器的语法介绍

Jun 07, 2016 pm 05:33 PM
mysql trigger o database

MySQL触发器是MySQL数据库非常重要的部分,下文对创建MySQL触发器及删除MySQL触发器作了详细的介绍,希望对您有所帮助。

MySQL触发器是MySQL数据库非常重要的部分,下文对创建MySQL触发器及删除MySQL触发器作了详细的介绍,希望对您有所帮助。

1、创建Mysql触发器:

语法:

CREATE TRIGGER trigger_name trigger_time trigger_event ON tbl_name
 FOR EACH ROW
 BEGIN
 trigger_stmt
 END;

CREATE TRIGGER trigger_name trigger_time trigger_event ON tbl_name FOR EACH ROW BEGIN trigger_stmt END;大写的为关键字

trigger_name:Mysql触发器的名字,我常用的命名规则t_name_tableName_(b|a)(i|u|d),t:触发器标识,name:英文名,,tableName:表名,

b(BEFORE):标识是触发事件之前,

a(AFTER):标识触发事件之后,

i(insert): 标识insert事件,

u(update):标识update事件,

d(delete):标识delete事件;

trigger_time:触发时间(BEFORE或AFTER)

trigger_event:事件名(insert或update或delete)

tbl_name:表名(必须是永久性表)

trigger_stmt:执行语句(可以是复合语名),使用别名OLD和NEW,能够引用与触发程序相关的表中的列。

2、删除Mysql解发器

语法:

DROP TRIGGER [schema_name.]trigger_name;

注意:以上操作均需SUPER权限

MySQL触发器的创建与删除
下面的文章主要描述的是MySQL触发器的正确创建步骤,MySQL触发器的删除,你如果对MySQL触发器的正确创建步骤,MySQL触发器的删除有兴趣的话你就可以点击以下的文章进行观看了。

1、创建MySQL触发器:

语法:
CREATE TRIGGER trigger_name trigger_time trigger_event ON tbl_name 
FOR EACH ROW 
BEGIN 
trigger_stmt 
END; 
CREATE TRIGGER trigger_name trigger_time trigger_event ON tbl_name 
FOR EACH ROW 
BEGIN 
trigger_stmt 
END; 

 

例子


CREATE TRIGGER SetUserHome after insert ON users 
FOR EACH ROW 
BEGIN 
update `users` set homeLocationX = 128, 
homeLocationY=128, homeLocationZ=30 
where uuid = NEW.uuid 
END 

以上的例子是错误的, 让本表进行触发时进行更新会让程序进入死循环。

更多详情见请继续阅读下一页的精彩内容


相关阅读:

利用MySQL触发器高性能造数据  

MySQL触发器的使用

MySQL触发器管理

MySQL触发器处理本表数据

Linux下MySQL触发器设置

linux

Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

AI Hentai Generator

AI Hentai Generator

Generate AI Hentai for free.

Hot Article

R.E.P.O. Energy Crystals Explained and What They Do (Yellow Crystal)
2 weeks ago By 尊渡假赌尊渡假赌尊渡假赌
Repo: How To Revive Teammates
4 weeks ago By 尊渡假赌尊渡假赌尊渡假赌
Hello Kitty Island Adventure: How To Get Giant Seeds
3 weeks ago By 尊渡假赌尊渡假赌尊渡假赌

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

Detailed tutorial on establishing a database connection using MySQLi in PHP Detailed tutorial on establishing a database connection using MySQLi in PHP Jun 04, 2024 pm 01:42 PM

How to use MySQLi to establish a database connection in PHP: Include MySQLi extension (require_once) Create connection function (functionconnect_to_db) Call connection function ($conn=connect_to_db()) Execute query ($result=$conn->query()) Close connection ( $conn->close())

iOS 18 adds a new 'Recovered' album function to retrieve lost or damaged photos iOS 18 adds a new 'Recovered' album function to retrieve lost or damaged photos Jul 18, 2024 am 05:48 AM

Apple's latest releases of iOS18, iPadOS18 and macOS Sequoia systems have added an important feature to the Photos application, designed to help users easily recover photos and videos lost or damaged due to various reasons. The new feature introduces an album called "Recovered" in the Tools section of the Photos app that will automatically appear when a user has pictures or videos on their device that are not part of their photo library. The emergence of the "Recovered" album provides a solution for photos and videos lost due to database corruption, the camera application not saving to the photo library correctly, or a third-party application managing the photo library. Users only need a few simple steps

How to handle database connection errors in PHP How to handle database connection errors in PHP Jun 05, 2024 pm 02:16 PM

To handle database connection errors in PHP, you can use the following steps: Use mysqli_connect_errno() to obtain the error code. Use mysqli_connect_error() to get the error message. By capturing and logging these error messages, database connection issues can be easily identified and resolved, ensuring the smooth running of your application.

How does Go WebSocket integrate with databases? How does Go WebSocket integrate with databases? Jun 05, 2024 pm 03:18 PM

How to integrate GoWebSocket with a database: Set up a database connection: Use the database/sql package to connect to the database. Store WebSocket messages to the database: Use the INSERT statement to insert the message into the database. Retrieve WebSocket messages from the database: Use the SELECT statement to retrieve messages from the database.

How to use database callback functions in Golang? How to use database callback functions in Golang? Jun 03, 2024 pm 02:20 PM

Using the database callback function in Golang can achieve: executing custom code after the specified database operation is completed. Add custom behavior through separate functions without writing additional code. Callback functions are available for insert, update, delete, and query operations. You must use the sql.Exec, sql.QueryRow, or sql.Query function to use the callback function.

How to handle database connections and operations using C++? How to handle database connections and operations using C++? Jun 01, 2024 pm 07:24 PM

Use the DataAccessObjects (DAO) library in C++ to connect and operate the database, including establishing database connections, executing SQL queries, inserting new records and updating existing records. The specific steps are: 1. Include necessary library statements; 2. Open the database file; 3. Create a Recordset object to execute SQL queries or manipulate data; 4. Traverse the results or update records according to specific needs.

Top 10 global digital currency trading apps recommended (2025 currency trading software ranking) Top 10 global digital currency trading apps recommended (2025 currency trading software ranking) Mar 12, 2025 pm 05:48 PM

This article recommends the top ten digital currency trading apps in the world, including Binance, OKX, Huobi Global, Coinbase, Kraken, Gate.io, KuCoin, Bitfinex, Gemini and Bitstamp. These platforms have their own characteristics in terms of transaction pair quantity, transaction speed, security, compliance, user experience, etc. For example, Binance is known for its high transaction speed and extensive services, while Coinbase is more suitable for novices. Choosing a platform that suits you requires comprehensive consideration of your own needs and risk tolerance. Learn about the world's mainstream digital currency trading platforms to help you conduct digital asset trading safely and efficiently.

How to install and register the btc trading app? How to install and register the btc trading app? Feb 21, 2025 pm 07:09 PM

This article will provide a detailed introduction to how to install and register a Bitcoin trading application. The Bitcoin trading app allows users to manage and trade cryptocurrencies such as Bitcoin. The article guides users through the installation and registration process step by step, including downloading applications, creating accounts, performing identity verification, and first deposit. The goal of the article is to provide beginners with clear and easy-to-understand guidelines to help them easily enter the world of Bitcoin trading.

See all articles