How to add, delete, modify and check mysql in php

<?php
$conn=mysql_connect(&#39;localhost&#39;,&#39;root&#39;,&#39;&#39;);
if(!$conn){
echo "connect failed";
exit;
}
$sql=&#39;use student&#39;;
mysql_query($sql,$conn);

$sql="insert into student(sname,sage) values('wx','18')";
$rs=mysql_query($sql,$conn);
if($rs){
    echo &#39;insert data success&#39;."<br />";
}else{
    echo &#39;insert data failed&#39;."<br />";
}

$sql="delete from student where sname='li'";
$rs=mysql_query($sql,$conn);
if($rs){
    echo &#39;del data success&#39;."<br />";
}else {
    echo &#39;del data failed&#39;."<br />";    
}

$sql="update student set sname='fu' where sname='pu'";
$rs=mysql_query($sql,$conn);
if($rs){
    echo &#39;update data success&#39;."<br />";
}else{
    echo &#39;update data failed&#39;."<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>">;
}
?>