Home Backend Development PHP Tutorial PHP 中要如何避免关联表

PHP 中要如何避免关联表

Jun 13, 2016 pm 01:39 PM
join mysql php

PHP 中要如何处理关联表

PHP code
<!--

Code highlighting produced by Actipro CodeHighlighter (freeware)
http://www.CodeHighlighter.com/

-->
比如有
用户表
文章表
评论表
收藏表

例子
用户A,发表一文章,被用户B评论,被用户C收藏,

如果对用户A执行删除操作,A发表的文章,文章的评论,收藏要怎么处理

类似问题应该按什么原则进行处理?

/*****************************************/
另外,php如何实现关联表的操作~添加,更新,删除


Copy after login


------解决方案--------------------
文章删除后把相应的评论、收藏也删除就行了。

多表可以连接。比如left join/right join/inner join 建议去看看mysql多表操作。
------解决方案--------------------
多表的操作:把相关数据分表操作,一张一张表来;
只有查询的时候关联在一起查询。
http://user.qzone.qq.com/937461184/blog/1330412851
------解决方案--------------------
楼主可以看看mysql的联表删除,也就是当你删除文章的时候,也在删除评论,和收藏的文章。
------解决方案--------------------
如果你上传了文件,同时被用户评论,收藏。
你要是删掉这个文件。那么其他用户的评论,和收藏该不该有。这是先考虑的问题。
如果你觉得这些东西都删掉。那么根据id删除,或者建立触发器等等。
如果你觉得没必要删除,那。。
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

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Roblox: Bubble Gum Simulator Infinity - How To Get And Use Royal Keys
3 weeks ago By 尊渡假赌尊渡假赌尊渡假赌
Nordhold: Fusion System, Explained
3 weeks ago By 尊渡假赌尊渡假赌尊渡假赌
Mandragora: Whispers Of The Witch Tree - How To Unlock The Grappling Hook
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)

Hot Topics

Java Tutorial
1669
14
PHP Tutorial
1273
29
C# Tutorial
1256
24
MySQL: The Database, phpMyAdmin: The Management Interface MySQL: The Database, phpMyAdmin: The Management Interface Apr 29, 2025 am 12:44 AM

MySQL and phpMyAdmin can be effectively managed through the following steps: 1. Create and delete database: Just click in phpMyAdmin to complete. 2. Manage tables: You can create tables, modify structures, and add indexes. 3. Data operation: Supports inserting, updating, deleting data and executing SQL queries. 4. Import and export data: Supports SQL, CSV, XML and other formats. 5. Optimization and monitoring: Use the OPTIMIZETABLE command to optimize tables and use query analyzers and monitoring tools to solve performance problems.

What is the significance of the session_start() function? What is the significance of the session_start() function? May 03, 2025 am 12:18 AM

session_start()iscrucialinPHPformanagingusersessions.1)Itinitiatesanewsessionifnoneexists,2)resumesanexistingsession,and3)setsasessioncookieforcontinuityacrossrequests,enablingapplicationslikeuserauthenticationandpersonalizedcontent.

Steps to add and delete fields to MySQL tables Steps to add and delete fields to MySQL tables Apr 29, 2025 pm 04:15 PM

In MySQL, add fields using ALTERTABLEtable_nameADDCOLUMNnew_columnVARCHAR(255)AFTERexisting_column, delete fields using ALTERTABLEtable_nameDROPCOLUMNcolumn_to_drop. When adding fields, you need to specify a location to optimize query performance and data structure; before deleting fields, you need to confirm that the operation is irreversible; modifying table structure using online DDL, backup data, test environment, and low-load time periods is performance optimization and best practice.

How to uninstall MySQL and clean residual files How to uninstall MySQL and clean residual files Apr 29, 2025 pm 04:03 PM

To safely and thoroughly uninstall MySQL and clean all residual files, follow the following steps: 1. Stop MySQL service; 2. Uninstall MySQL packages; 3. Clean configuration files and data directories; 4. Verify that the uninstallation is thorough.

An efficient way to batch insert data in MySQL An efficient way to batch insert data in MySQL Apr 29, 2025 pm 04:18 PM

Efficient methods for batch inserting data in MySQL include: 1. Using INSERTINTO...VALUES syntax, 2. Using LOADDATAINFILE command, 3. Using transaction processing, 4. Adjust batch size, 5. Disable indexing, 6. Using INSERTIGNORE or INSERT...ONDUPLICATEKEYUPDATE, these methods can significantly improve database operation efficiency.

How to use MySQL functions for data processing and calculation How to use MySQL functions for data processing and calculation Apr 29, 2025 pm 04:21 PM

MySQL functions can be used for data processing and calculation. 1. Basic usage includes string processing, date calculation and mathematical operations. 2. Advanced usage involves combining multiple functions to implement complex operations. 3. Performance optimization requires avoiding the use of functions in the WHERE clause and using GROUPBY and temporary tables.

Composer: The Package Manager for PHP Developers Composer: The Package Manager for PHP Developers May 02, 2025 am 12:23 AM

Composer is a dependency management tool for PHP, and manages project dependencies through composer.json file. 1) parse composer.json to obtain dependency information; 2) parse dependencies to form a dependency tree; 3) download and install dependencies from Packagist to the vendor directory; 4) generate composer.lock file to lock the dependency version to ensure team consistency and project maintainability.

Detailed explanation of the installation steps of MySQL on macOS system Detailed explanation of the installation steps of MySQL on macOS system Apr 29, 2025 pm 03:36 PM

Installing MySQL on macOS can be achieved through the following steps: 1. Install Homebrew, using the command /bin/bash-c"$(curl-fsSLhttps://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)". 2. Update Homebrew and use brewupdate. 3. Install MySQL and use brewinstallmysql. 4. Start MySQL service and use brewservicesstartmysql. After installation, you can use mysql-u

See all articles