Detailed explanation of the effect of the secondary linkage menu implemented by php mysql, mysql linkage

Table of Contents

Detailed explanation of the secondary linkage menu effect implemented by php mysql, mysql linkage

Home

Backend Development

PHP Tutorial

Detailed explanation of the effect of the secondary linkage menu implemented by php mysql, mysql linkage_PHP tutorial

WBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWBOYWB

Jul 12, 2016 am 08:52 AM

html code mysql php

This article describes the secondary linkage menu effect implemented by php mysql. Share it with everyone for your reference, the details are as follows:

<!--php+mysql二级联动-->
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>生成学院专业级联下拉菜单测试 </title>
</head>
<body>
<&#63; //
/***********************************************
** 功 能： php+mysql+javascript实现学院专业二级级联下拉框
** 数据库：数据库名（ dms）、数据表（ colleges、 majors）
** 表 colleges中字段： college_id（ id编号）、 name（学院名）
** 表 majors中的字段： major_id（ id编号）、 college_id（学院 ID）、 name（学院名）
** version 1.0
** 作 者： wu yaowen
***********************************************/
//****************** 连接选择数据库 ***************
$link = mysql_connect("localhost", "root", "123456")
  or die("Could not connect : " . mysql_error());
mysql_select_db("dms") or die("Could not select database");
//******************提取学院信息 ******************
$queryCol = "select * from colleges order by college_id ";
mysql_query("SET NAMES 'gb2312'");
$result1 = mysql_query($queryCol) or die("Query failed : " . mysql_error());
$colleges = array();
while( $row1 = mysql_fetch_array($result1) )
{
  $colleges[] = $row1;
}
//print_r ($forum_data);
mysql_free_result($result1);
//**************获取专业信息 **************  
$queryMaj = "select * from majors order by college_id desc";
mysql_query("SET NAMES 'gb2312'");
if( !($result2 = mysql_query($queryMaj)) )
{
  die('Could not query t_city list');
}
$majors = array();
while( $row2 = mysql_fetch_array($result2) )
{
  $majors[] = $row2;
}
mysql_free_result($result2);
&#63;>
<!--************ JavaScript处理 college-onChange *************-->
<script language = "JavaScript">
 var majorCount; // 存储专业记录条数
 // form_majors[] 储存专业 major数据，如 {(1,1,电子商务 ),(4,1,计算机科学 ),(3,2,古典文学 )}
 form_majors = new Array();
 <&#63;php
   $num2 = count($majors); // $num2 获取专业表中记录的个数
 &#63;>
   majorCount = <&#63;php echo $num2;&#63;>;
 <&#63;
   for($j=0;$j<$num2;$j++) // 从 0开始取出上面 majors[]中存储的专业数据填充数组
 {
 &#63;>
   form_majors[<&#63;echo $j;&#63;>] = new Array("<&#63;echo $majors[$j]['major_id'];&#63;>","<&#63;echo $majors[$j]['college_id'];&#63;>","<&#63;echo $majors[$j]['name'];&#63;>");
 <&#63;php
 }
 &#63;>
 function changeCollege(college_id)
 {
   document.stu_add_form.major.length = 0;
   var id=id;
   var j;
   document.stu_add_form.major.options[0] = new Option('==选择专业 ==',''); // label的 value为空 ' '
   for (j=0;j < majorCount; j++) // 从 0开始判断
   {
    if (form_majors[j][1] == college_id) // if college_id等于选择的学院的 id
    {
       document.stu_add_form.major.options[document.stu_add_form.major.length] = new Option(form_majors[j][2], form_majors[j][0]);
    }
   }
 }
</script>
<!--********************页面表单 *************************-->
<form name="stu_add_form" method="post">
选择： <select name="college" onChange="changeCollege(document.stu_add_form.college.options[document.stu_add_form.college.selectedIndex].value)" size="1">
<option selected>==请选择学院 ==</option>
<&#63;php
$num = count($colleges);
for($i=0;$i<$num;$i++)
{
&#63;>
<option value="<&#63;echo $colleges[$i]['college_id'];&#63;>"><&#63;echo $colleges[$i]['name'];&#63;></option>
<&#63;
}
&#63;>
</select>
<select name="major">
<option selected value="">==选择专业 ==</option>
</select>
</form>
</body>
</html>

Copy after login

sql statement:

--
-- 表的结构 `colleges`
--
CREATE TABLE IF NOT EXISTS `colleges` (
 `college_id` int(8) NOT NULL auto_increment COMMENT '学院编号自动增加',
 `name` varchar(40) NOT NULL COMMENT '学院名称',
 PRIMARY KEY (`college_id`),
 UNIQUE KEY `name` (`name`)
) ENGINE=InnoDB DEFAULT CHARSET=gb2312 AUTO_INCREMENT=7 ;
--
-- 导出表中的数据 `colleges`
--
INSERT INTO `colleges` (`college_id`, `name`) VALUES
(4, '化学与化工学院'),
(1, '计算机与信息科学学院'),
(6, '美术学院'),
(2, '文学院'),
(5, '音乐学院'),
(3, '政治与公共管理学院');
--
-- 表的结构 `majors`
--
CREATE TABLE IF NOT EXISTS `majors` (
 `major_id` int(8) NOT NULL auto_increment COMMENT '专业号，自动增加',
 `name` varchar(40) NOT NULL COMMENT '专业名',
 `college_id` int(8) default NULL COMMENT '所在学院',
 `counsellor_id` int(10) default NULL COMMENT '辅导员',
 PRIMARY KEY (`major_id`),
 UNIQUE KEY `college_id` (`college_id`,`counsellor_id`)
) ENGINE=InnoDB DEFAULT CHARSET=gb2312 AUTO_INCREMENT=8 ;
--
-- 导出表中的数据 `majors`
--
INSERT INTO `majors` (`major_id`, `name`, `college_id`, `counsellor_id`) VALUES
(1, '电子商务', 1, 1),
(2, '音乐视唱', 5, 1),
(3, '古典文学', 2, 1),
(4, '计算机科学', 1, NULL),
(5, '自动化', 1, NULL),
(6, '现代文学', 2, NULL),
(7, '新闻写作', 2, NULL);

Copy after login

Readers who are interested in more PHP-related content can check out the special topics of this site: "Summary of PHP database operation skills based on pdo", "PHP MongoDB database operation skills collection", "php object-oriented programming introductory tutorial", "php Summary of String Usage", "Introduction Tutorial on PHP MySQL Database Operation" and "Summary of PHP Common Database Operation Skills"

I hope this article will be helpful to everyone in PHP programming.

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

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

Assassin's Creed Shadows: Seashell Riddle Solution

3 weeks ago By DDD

What's New in Windows 11 KB5054979 & How to Fix Update Issues

2 weeks ago By DDD

Where to find the Crane Control Keycard in Atomfall

3 weeks ago By DDD

Assassin's Creed Shadows - How To Find The Blacksmith And Unlock Weapon And Armour Customisation

1 months ago By DDD

Roblox: Dead Rails - How To Complete Every Challenge

3 weeks ago By DDD

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

Where is the login entrance for gmail email?

7613

CakePHP Tutorial

1387

What is the format of the account name of steam

win11 activation key permanent

nyt connections hints and answers

136

Related knowledge

PHP and Python: Comparing Two Popular Programming Languages Apr 14, 2025 am 12:13 AM

PHP and Python each have their own advantages, and choose according to project requirements. 1.PHP is suitable for web development, especially for rapid development and maintenance of websites. 2. Python is suitable for data science, machine learning and artificial intelligence, with concise syntax and suitable for beginners.

PHP's Current Status: A Look at Web Development Trends Apr 13, 2025 am 12:20 AM

PHP remains important in modern web development, especially in content management and e-commerce platforms. 1) PHP has a rich ecosystem and strong framework support, such as Laravel and Symfony. 2) Performance optimization can be achieved through OPcache and Nginx. 3) PHP8.0 introduces JIT compiler to improve performance. 4) Cloud-native applications are deployed through Docker and Kubernetes to improve flexibility and scalability.

PHP: A Key Language for Web Development Apr 13, 2025 am 12:08 AM

PHP is a scripting language widely used on the server side, especially suitable for web development. 1.PHP can embed HTML, process HTTP requests and responses, and supports a variety of databases. 2.PHP is used to generate dynamic web content, process form data, access databases, etc., with strong community support and open source resources. 3. PHP is an interpreted language, and the execution process includes lexical analysis, grammatical analysis, compilation and execution. 4.PHP can be combined with MySQL for advanced applications such as user registration systems. 5. When debugging PHP, you can use functions such as error_reporting() and var_dump(). 6. Optimize PHP code to use caching mechanisms, optimize database queries and use built-in functions. 7

PHP: The Foundation of Many Websites Apr 13, 2025 am 12:07 AM

The reasons why PHP is the preferred technology stack for many websites include its ease of use, strong community support, and widespread use. 1) Easy to learn and use, suitable for beginners. 2) Have a huge developer community and rich resources. 3) Widely used in WordPress, Drupal and other platforms. 4) Integrate tightly with web servers to simplify development deployment.

MySQL's Place: Databases and Programming Apr 13, 2025 am 12:18 AM

MySQL's position in databases and programming is very important. It is an open source relational database management system that is widely used in various application scenarios. 1) MySQL provides efficient data storage, organization and retrieval functions, supporting Web, mobile and enterprise-level systems. 2) It uses a client-server architecture, supports multiple storage engines and index optimization. 3) Basic usages include creating tables and inserting data, and advanced usages involve multi-table JOINs and complex queries. 4) Frequently asked questions such as SQL syntax errors and performance issues can be debugged through the EXPLAIN command and slow query log. 5) Performance optimization methods include rational use of indexes, optimized query and use of caches. Best practices include using transactions and PreparedStatemen

The Enduring Relevance of PHP: Is It Still Alive? Apr 14, 2025 am 12:12 AM

PHP is still dynamic and still occupies an important position in the field of modern programming. 1) PHP's simplicity and powerful community support make it widely used in web development; 2) Its flexibility and stability make it outstanding in handling web forms, database operations and file processing; 3) PHP is constantly evolving and optimizing, suitable for beginners and experienced developers.

PHP vs. Python: Core Features and Functionality Apr 13, 2025 am 12:16 AM

PHP and Python each have their own advantages and are suitable for different scenarios. 1.PHP is suitable for web development and provides built-in web servers and rich function libraries. 2. Python is suitable for data science and machine learning, with concise syntax and a powerful standard library. When choosing, it should be decided based on project requirements.

PHP vs. Other Languages: A Comparison Apr 13, 2025 am 12:19 AM

PHP is suitable for web development, especially in rapid development and processing dynamic content, but is not good at data science and enterprise-level applications. Compared with Python, PHP has more advantages in web development, but is not as good as Python in the field of data science; compared with Java, PHP performs worse in enterprise-level applications, but is more flexible in web development; compared with JavaScript, PHP is more concise in back-end development, but is not as good as JavaScript in front-end development.

See all articles