AJAX與Mysql
Penjelasan contoh - pangkalan data MySQL
Dalam contoh di atas, jadual pangkalan data yang kami gunakan adalah seperti berikut:
Penjelasan contoh - halaman HTML
Apabila pengguna memilih pengguna dalam senarai juntai bawah di atas, panggilan dipanggil "showUser( "akan dilaksanakan )" fungsi. Fungsi ini dicetuskan oleh peristiwa "onchange":
<html>
<head>
<script>
function showUser(str)
{
if (str=="")
{
document.getElementById("txtHint").innerHTML="";
return;
}
if (window.XMLHttpRequest)
{
// IE7+, Firefox, Chrome, Opera, Safari 瀏覽器執(zhí)行代碼
xmlhttp=new XMLHttpRequest();
}
else
{
// IE6, IE5 瀏覽器執(zhí)行代碼
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
}
xmlhttp.onreadystatechange=function()
{
if (xmlhttp.readyState==4 && xmlhttp.status==200)
{
document.getElementById("txtHint").innerHTML=xmlhttp.responseText;
}
}
xmlhttp.open("GET","getuser.php?q="+str,true);
xmlhttp.send();
}
</script>
</head>
<body>
<form>
<select name="users" onchange="showUser(this.value)">
<option value="">Select a person:</option>
<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>
<br>
<div id="txtHint"><b>Person info will be listed here.</b></div>
</body>
</html>showUser() Fungsi akan melakukan langkah berikut
·?????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????? tidak kandungan)
Fail PHP
Halaman pelayan yang dipanggil di atas melalui JavaScript dinamakan fail PHP "getuser.php".
Kod sumber dalam "getuser.php" menjalankan pertanyaan terhadap pangkalan data MySQL dan mengembalikan keputusan dalam jadual HTML: <?php
$q=$_GET["q"];
$con = mysqli_connect('localhost','peter','abc123','my_db');
if (!$con)
{
die('Could not connect: ' . mysqli_error($con));
}
mysqli_select_db($con,"ajax_demo");
$sql="SELECT * FROM user WHERE id = '".$q."'";
$result = mysqli_query($con,$sql);
echo "<table border='1'>
<tr>
<th>Firstname</th>
<th>Lastname</th>
<th>Age</th>
<th>Hometown</th>
<th>Job</th>
</tr>";
while($row = mysqli_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>" . $row['Job'] . "</td>";
echo "</tr>";
}
echo "</table>";
mysqli_close($con);
?>Penjelasan: Apabila pertanyaan dihantar daripada JavaScript ke PHP fail , akan berlaku: 1 PHP membuka sambungan ke pangkalan data MySQL
2 Mencari pengguna yang dipilih
3. dan menghantarnya kembali pemegang tempat "txtHint"
