search
HomeBackend DevelopmentPHP TutorialPHP+MySQL实现下拉框展示数据库信息

PHP+MySQL实现下拉框显示数据库信息

本帖最后由 kitttyfjy12 于 2012-05-20 17:18:03 编辑

  Classroom research



  

CRMS - Classroom research



  

    
      
        
         
      
      
  
  
      

      
        
      
    
Classroom ID
Course ID

        

  




1、我希望在第一个框输入课室号,第二框通过下拉框显示数据库中course2表的CID的内容。
这应该就是不对的,毫无头绪,不知道怎么实现。求详细代码!
2、怎样实现填写其中一个数据(即不用填两个)就可以查询数据?

------解决思路----------------------
仅供参考:
<br /><?php<br />/* Created on [2012-5-16] */<br />#查询标题信息<br />$sql="select * from table";<br />	$res=mysql_query($sql);<br />	if(!$res) die("SQL: {$sql} <br>Error:".mysql_error());<br />	if(mysql_affected_rows() > 0){<br />		$titles = array();<br />		while($rows = mysql_fetch_array(MYSQL_ASSOC)){<br />			array_push($titles,$rows);<br />		}<br />	}<br />?><br /><br /><table border=1><br /><?php foreach($titles as $row_Recordset_task){ ?><br />	<tr><br />		<td><br />			<a href="javascript:void(0)" onclick="record(<?=$row_Recordset_task['TID']?>)" ><br />				<?=$row_Recordset_task['csa_title']?><br />			</a><br />		</td><br />	</tr><br /><?php } ?><br /></table><br /><div id="show"></div><br /><br /><br /><form name="frm"><br /><select name="s1" onChange="redirec(this.value)"><br /> <option selected>请选择</option><br /> <option value="1">内科</option><br /> <option value="2">内科</option><br /> <option value="3">内科</option><br /></select><br /><div id="s2"></div><br /></form><br /><script><br />//Ajax<br />var xmlHttp;<br /><br />	function createXMLHttpRequest() {<br />		if(window.XMLHttpRequest) {<br />			xmlHttp = new XMLHttpRequest();<br />		} else if (window.ActiveXObject) {<br />			xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");<br />		}<br />	}<br /><br />	function record(id){<br />		createXMLHttpRequest();<br />		url = "action.php?id="+id+"&ran="+Math.random();<br />		method = "GET";<br />		xmlHttp.open(method,url,true);<br />		xmlHttp.onreadystatechange = show;<br />		xmlHttp.send(null);<br />	}<br /><br />	function show(){<br />		if (xmlHttp.readyState == 4){<br />			if (xmlHttp.status == 200){<br />				var text = xmlHttp.responseText;<br />				document.getElementById("s2").innerHTML = text;<br />			}else {<br />				alert("response error code:"+xmlHttp.status);<br />			}<br />		}<br />	}<br /></script><br /><?php<br />#action.php<br />if(isset($_GET['id'])){<br />	$sql="select * from table where id=".$_GET['id'];<br />	$res=mysql_query($sql);<br />	if(!$res) die("SQL: {$sql} <br>Error:".mysql_error());<br />	if(mysql_affected_rows() > 0){<br />		$arrMenu=array();<br />		while($rows = mysql_fetch_array(MYSQL_ASSOC)){<br />			array_push($arrMenu,$rows);<br />		}<br />	}<br />	mysql_close();<br />	if(!empty($arrMenu)){<br />		echo "<select name='menu2'>";<br />		foreach($arrMenu as $item2){<br />			echo "<option value='{$item2['id']}'>{$item2['name']}</option>";<br />		}<br />		echo "</select>";<br />	}<br />}<br /><br />?><br /><br />

------解决思路----------------------
就这么简单,不需要上面那么复杂!!伱直接复制过去就可以用了。。。。

//require_once('conn.php'); //伱最好写个连接数据库的文件 每次包含一下就行了! 而且要写在最上面

//最好把下面三行写在conn.php文件里 以后每次用时 向上面那样包含一下就OK了!!
$con = mysql_connect("localhost","root","***") or die("错误信息:".mysql_error());   //连接
$db = mysql_select_db("表course2所在的数据库名");   //这个要不写就取不着数据 但不会报错
mysql_query("set names gb2312");                  

?>
nbsp;html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">



无标题文档






------解决思路----------------------
搞这么复杂?script标签在代码底部加也行啊,只要有:
<br /><script><br />//Ajax<br />var xmlHttp;<br /><br />    function createXMLHttpRequest() {<br />        if(window.XMLHttpRequest) {<br />            xmlHttp = new XMLHttpRequest();<br />        } else if (window.ActiveXObject) {<br />            xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");<br />        }<br />    }<br /><br />    function record(id){<br />        createXMLHttpRequest();<br />//指定目标地址及参数<br />        url = "action.php?id="+id+"&ran="+Math.random();<br />        method = "GET";<br />        xmlHttp.open(method,url,true);<br />        xmlHttp.onreadystatechange = show;<br />        xmlHttp.send(null);<br />    }<br /><br />    function show(){<br />        if (xmlHttp.readyState == 4){<br />            if (xmlHttp.status == 200){<br />//回调函数,返回的后端结果<br />                var text = xmlHttp.responseText;<br />                document.getElementById("s2").innerHTML = text;<br />            }else {<br />                alert("response error code:"+xmlHttp.status);<br />            }<br />        }<br />    }<br /></script><br />

能运行就行
Statement
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
What are the advantages of using a database to store sessions?What are the advantages of using a database to store sessions?Apr 24, 2025 am 12:16 AM

The main advantages of using database storage sessions include persistence, scalability, and security. 1. Persistence: Even if the server restarts, the session data can remain unchanged. 2. Scalability: Applicable to distributed systems, ensuring that session data is synchronized between multiple servers. 3. Security: The database provides encrypted storage to protect sensitive information.

How do you implement custom session handling in PHP?How do you implement custom session handling in PHP?Apr 24, 2025 am 12:16 AM

Implementing custom session processing in PHP can be done by implementing the SessionHandlerInterface interface. The specific steps include: 1) Creating a class that implements SessionHandlerInterface, such as CustomSessionHandler; 2) Rewriting methods in the interface (such as open, close, read, write, destroy, gc) to define the life cycle and storage method of session data; 3) Register a custom session processor in a PHP script and start the session. This allows data to be stored in media such as MySQL and Redis to improve performance, security and scalability.

What is a session ID?What is a session ID?Apr 24, 2025 am 12:13 AM

SessionID is a mechanism used in web applications to track user session status. 1. It is a randomly generated string used to maintain user's identity information during multiple interactions between the user and the server. 2. The server generates and sends it to the client through cookies or URL parameters to help identify and associate these requests in multiple requests of the user. 3. Generation usually uses random algorithms to ensure uniqueness and unpredictability. 4. In actual development, in-memory databases such as Redis can be used to store session data to improve performance and security.

How do you handle sessions in a stateless environment (e.g., API)?How do you handle sessions in a stateless environment (e.g., API)?Apr 24, 2025 am 12:12 AM

Managing sessions in stateless environments such as APIs can be achieved by using JWT or cookies. 1. JWT is suitable for statelessness and scalability, but it is large in size when it comes to big data. 2.Cookies are more traditional and easy to implement, but they need to be configured with caution to ensure security.

How can you protect against Cross-Site Scripting (XSS) attacks related to sessions?How can you protect against Cross-Site Scripting (XSS) attacks related to sessions?Apr 23, 2025 am 12:16 AM

To protect the application from session-related XSS attacks, the following measures are required: 1. Set the HttpOnly and Secure flags to protect the session cookies. 2. Export codes for all user inputs. 3. Implement content security policy (CSP) to limit script sources. Through these policies, session-related XSS attacks can be effectively protected and user data can be ensured.

How can you optimize PHP session performance?How can you optimize PHP session performance?Apr 23, 2025 am 12:13 AM

Methods to optimize PHP session performance include: 1. Delay session start, 2. Use database to store sessions, 3. Compress session data, 4. Manage session life cycle, and 5. Implement session sharing. These strategies can significantly improve the efficiency of applications in high concurrency environments.

What is the session.gc_maxlifetime configuration setting?What is the session.gc_maxlifetime configuration setting?Apr 23, 2025 am 12:10 AM

Thesession.gc_maxlifetimesettinginPHPdeterminesthelifespanofsessiondata,setinseconds.1)It'sconfiguredinphp.iniorviaini_set().2)Abalanceisneededtoavoidperformanceissuesandunexpectedlogouts.3)PHP'sgarbagecollectionisprobabilistic,influencedbygc_probabi

How do you configure the session name in PHP?How do you configure the session name in PHP?Apr 23, 2025 am 12:08 AM

In PHP, you can use the session_name() function to configure the session name. The specific steps are as follows: 1. Use the session_name() function to set the session name, such as session_name("my_session"). 2. After setting the session name, call session_start() to start the session. Configuring session names can avoid session data conflicts between multiple applications and enhance security, but pay attention to the uniqueness, security, length and setting timing of session names.

See all articles

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 Tools

mPDF

mPDF

mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),

VSCode Windows 64-bit Download

VSCode Windows 64-bit Download

A free and powerful IDE editor launched by Microsoft

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

PhpStorm Mac version

PhpStorm Mac version

The latest (2018.2.1) professional PHP integrated development tool

ZendStudio 13.5.1 Mac

ZendStudio 13.5.1 Mac

Powerful PHP integrated development environment