php如何对mysql进行增删修查

<?php
$conn=mysql_connect('localhost','root','');
if(!$conn){
echo "connect failed";
exit;
}
$sql='use student';
mysql_query($sql,$conn);

$sql="insert into student(sname,sage) values('wx','18')";
$rs=mysql_query($sql,$conn);
if($rs){
 echo 'insert data success'."<br />";
}else{
 echo 'insert data failed'."<br />";
}

$sql="delete from student where sname='li'";
$rs=mysql_query($sql,$conn);
if($rs){
 echo 'del data success'."<br />";
}else {
 echo 'del data failed'."<br />"; 
}

$sql="update student set sname='fu' where sname='pu'";
$rs=mysql_query($sql,$conn);
if($rs){
 echo 'update data success'."<br />";
}else{
 echo 'update data failed'."<br />";
}

$sql="select * from student";
$rs=mysql_query($sql,$conn);
var_dump($rs);
while($row=mysql_fetch_object($rs)){
print_r($row);
echo ' ';
echo $row->sname ."<br>">;
}
?>