两个有关联的表的循环有关问题
两个有关联的表的循环问题
我现在有两个数据库表
课程表subject
id subjectname
1 语文
2 数学
3 英语
班级所选课程表classsubject
id classid(班级表id) subjectid(课程表id)
1 1 1
2 1 2
3 1 1
我需要实现页面先以复选框的形式显示出课程表的的所有课程
然后,根据班级id,查询出相对应的课程id,相应的课程复选框就成为选中的状态
如果班级id为1
则页面显示如下
- HTML code
<!-- Code highlighting produced by Actipro CodeHighlighter (freeware) http://www.CodeHighlighter.com/ --> <input type="checkbox" name="subject[]" value="1" checked>语文 <input type="checkbox" name="subject[]" value="2" checked>数学 <input type="checkbox" name="subject[]" value="3">英语
应该怎么实现,前辈们给看看啊
------解决方案--------------------
- SQL code
SELECT s.*, c.subjectid FROM subject AS s LEFT JOIN classsubject AS c ON s.id=c.subjectid AND c.classid=1 <br><font color="#e78608">------解决方案--------------------</font><br>用1楼查询找出班级所有已选课程数组,然后查询出所有课程数组,2个foreach循环嵌套(可能还有其他更好的办法)就能给所有课程数组标记出哪些是已选的,然后循环输出,已选标记的checked就可以了。 <div class="clear"> </div>

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

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

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



Alipay PHP...

JWT is an open standard based on JSON, used to securely transmit information between parties, mainly for identity authentication and information exchange. 1. JWT consists of three parts: Header, Payload and Signature. 2. The working principle of JWT includes three steps: generating JWT, verifying JWT and parsing Payload. 3. When using JWT for authentication in PHP, JWT can be generated and verified, and user role and permission information can be included in advanced usage. 4. Common errors include signature verification failure, token expiration, and payload oversized. Debugging skills include using debugging tools and logging. 5. Performance optimization and best practices include using appropriate signature algorithms, setting validity periods reasonably,

Article discusses late static binding (LSB) in PHP, introduced in PHP 5.3, allowing runtime resolution of static method calls for more flexible inheritance.Main issue: LSB vs. traditional polymorphism; LSB's practical applications and potential perfo

Session hijacking can be achieved through the following steps: 1. Obtain the session ID, 2. Use the session ID, 3. Keep the session active. The methods to prevent session hijacking in PHP include: 1. Use the session_regenerate_id() function to regenerate the session ID, 2. Store session data through the database, 3. Ensure that all session data is transmitted through HTTPS.

The application of SOLID principle in PHP development includes: 1. Single responsibility principle (SRP): Each class is responsible for only one function. 2. Open and close principle (OCP): Changes are achieved through extension rather than modification. 3. Lisch's Substitution Principle (LSP): Subclasses can replace base classes without affecting program accuracy. 4. Interface isolation principle (ISP): Use fine-grained interfaces to avoid dependencies and unused methods. 5. Dependency inversion principle (DIP): High and low-level modules rely on abstraction and are implemented through dependency injection.

How to automatically set the permissions of unixsocket after the system restarts. Every time the system restarts, we need to execute the following command to modify the permissions of unixsocket: sudo...

How to debug CLI mode in PHPStorm? When developing with PHPStorm, sometimes we need to debug PHP in command line interface (CLI) mode...

Static binding (static::) implements late static binding (LSB) in PHP, allowing calling classes to be referenced in static contexts rather than defining classes. 1) The parsing process is performed at runtime, 2) Look up the call class in the inheritance relationship, 3) It may bring performance overhead.
