MySQL循环遍历执行查询SQL语句结果的方法

<?php
$conn=mysql_connect("localhost","root","123456") or die(mysql_error());
$set=mysql_select_db("vt",$conn)or die(mysql_error());
mysql_query("SET NAMES `GBK`");
$sql="SELECT * FROM `user`";
$query=mysql_query($sql);
?>
<table>
<tr>
<td>id</td>
<td>username</td>
</tr>
<?php
while($row=mysql_fetch_array($query))
{
?>
<tr>
<td><?php echo $row["id"]?></td>
<td><?php echo $row["username"]?></td>
</tr>
<?php
}
?>
</table>