Examples of PHP and Ajax MySQL databases

Examples of PHP and Ajax MySQL databases

The user information is listed here.

This example contains four elements:

MySQL Database
A simple HTML form
A JavaScript
A PHP Web page



Database
We will use this database in this example to look like this:

Age

ID	FirstName	LastName		Hometown	Job
1	Peter	Griffin	41	Quahog	Brewery
2	Lois	Griffin	40	Newport	Piano Teacher
3	Joseph	Swanson	39	Quahog	Police Officer
4	Glenn	Quagmire	41	Quahog	Pilot

 
  
<form> 
Select a User:
<select name= "users" onchange= "Showuser (this.value)" >
<option Value= "1" >peter griffin</option>
<option value= "2" >lois griffin</option>-<option
Value= "3" >glenn quagmire</option>
<option value= "4" >joseph swanson</option>-</
Select>
</form>
 
  
<p>
<div id= "Txthint" ><b>user info would be listed here.</b></div>
</p>
 
  
</body>
 
  
   
     

    
      

      
For example the explanation-the H tml form
As you can see, this is just a simple HTML format for the dropdown box called "User" name and "id" from the database, as a choice of value.

The following form of the paragraph contains the so-called "Txthint" of a zone. The zone is a network server that is used as a location for reservation information retrieval.

When the user selects the data, a function called "showuser ()" executes. The function performed is the "onchange" event that is raised.

In other words: each change in the value of the user in the dropdown box, function Showuser () is invoked.




The JavaScript
This is the JavaScript code stored in the file "Selectuser.js":
      

    
      
var xmlHttp

    
      
function Showuser (str)
{ 
xmlhttp=getxmlhttpobject ()
if (xmlhttp==null)
 {
 alert ("Browser does Not support HTTP Request "]
 return
 }
var url=" getuser.php "
url=url+
" q= "+str url=url+" &sid= "+math.random ()
xmlhttp.onreadystatechange=statechanged 
xmlhttp.open (" Get ", Url,true)
Xmlhttp.send (null)
}

    
      
function statechanged () 
{ 
if (xmlhttp.readystate==4 | | xmlhttp.readystate== "complete")
 { 
 document.getElementById ("Txthint"). Innerhtml=xmlhttp.responsetext 
 } 
}

    
      
function Getxmlhttpobject ()
{
var xmlhttp=null;
Try
 {
 //Firefox, Opera 8.0+, Safari
 xmlhttp=new XMLHttpRequest ();
 }
catch (E)
 {
 //internet Explorer
 try
  {
  xmlhttp=new activexobject ("msxml2.xmlhttp");
  }
 catch (E)
  {
  xmlhttp=new activexobject ("Microsoft.XMLHTTP");
  }
return xmlHttp;
}

    
      
     
       

      
        

        
 For example 
 the statechanged () and Getxmlhttpobject functions are the same as PHP's AJAX chapters suggest that you can go there to explain these. 
 
 The Showuser () function 
 
 If an item is selected in the Drop-down box to perform the following function: 
 
 calls Getxmlhttpobject function to create a XMLHTTP object 
 defines the URL (file) to be transmitted to the server 
 Add a parameter (Q) to the URL with the content of the dropdown box 
 to add a random number to prevent the server from using the cache file 
 Call StateChanged When the change is triggered 
 opening XMLHTTP object with a specific URL. 
 Send an HTTP request to the server 
 
 
 
 PHP page 
 The server's page requirements for JavaScript, is a simple php file named "getuser.php". 
 
 The Web page is written in PHP and uses a MySQL database. 
 
 The code runs a database of SQL queries and returns the result as an HTML table: 
        

      
        
 <?php $q =$_get["Q"];
$con = mysql_connect (' localhost ', ' Peter ', ' abc123 ');
 if (! $con) {die (' could not connect: '. Mysql_error ());

} mysql_select_db ("Ajax_demo", $con);

$sql = "SELECT * FROM user WHERE id = '". $q. "'";

$result = mysql_query ($sql); echo "<table border= ' 1 ' > <tr> <th>Firstname</th> <th>Lastname</th> <th>age

</th> <th>Hometown</th> <th>Job</th> </tr> ";
 while ($row = Mysql_fetch_array ($result)) {echo "<tr>"; echo "<td>". $row [' FirstName '].
 "</td>"; echo "<td>". $row [' LastName '].
 "</td>"; echo "<td>". $row [' Age '].
 "</td>"; echo "<td>". $row [' Hometown '].
 "</td>"; echo "<td>". $row [' Job '].
 "</td>";
 echo "</tr>";

echo "</table>"; Mysql_close ($con)?> reprint please indicate from Http://www.111cn.net/wy/yw.html