// The following example will demonstrate how a web page can fetch information from a database with AJAX:


Example Explained - The HTML Page

When a user selects a user in the dropdown list above, a function called "showUser()" is executed. The function is triggered by the "onchange" event:








Select a person:
Peter Griffin
Lois Griffin
Glenn Quagmire
Joseph Swanson

Person info will be listed here.

The showUser() function does the following:

* Check if a person is selected
* Create an XMLHttpRequest object
* Create the function to be executed when the server response is ready
* Send the request off to a file on the server
* Notice that a parameter (q) is added to the URL (with the content of the dropdown list)

The PHP File

The page on the server called by the JavaScript above is a PHP file called "getuser.php".

The source code in "getuser.php" runs a query against a MySQL database, and returns the result in an HTML table:
$q=$_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 "






";

while($row = mysql_fetch_array($result))
{
echo "";
echo "";
echo "";
echo "";
echo "";
echo "";
echo "";
}
echo "

Firstname	Lastname	Age	Hometown	Job
" . $row['FirstName'] . "	" . $row['LastName'] . "	" . $row['Age'] . "	" . $row['Hometown'] . "	" . $row['Job'] . "

";

mysql_close($con);
?>

Explanation: When the query is sent from the JavaScript to the PHP file, the following happens:

1. PHP opens a connection to a MySQL server
2. The correct person is found
3. An HTML table is created, filled with data, and sent back to the "txtHint" placeholder



Truck Games
Sports Games
Beyin

Read more: http://feeds.dzone.com/~r/dzone/snippets/~3/Cmy78e6i9K0/11705