Write a PHP program to implement Create, Read, Update and Display operations on Teacher table with attributes(tid, tname, address, subject). (Use Radio Buttons)

Teacher.php
<HTML>
<BODY>
<FORM method=POST action="<?php echo $_SERVER['PHP_SELF'] ?>">
<b><h3>Perform operations on the TEACHER Table</b><BR>
<INPUT type=radio name="choice" value="1">Create<BR>
<INPUT type=radio name="choice" value="2">Insert<BR>
<INPUT type=radio name="choice" value="3">Update<BR>
<INPUT type=radio name="choice" value="4">Delete<BR>
<INPUT type=submit name=submit value="Operation Perform"><BR>
</FORM>
<?php
$hn="localhost";
$db="Teach";
$un="root";
$psw="";
$link=mysqli_connect($hn,$un,$psw,$db);
if(isset($_POST['submit']))
{
    $ch=$_POST['choice'];
            if($ch=='1')
    {
                        if(!$link)
                        {
                                    die('connection faild:'.mysql_error());
                        }
                                                $sql="create table teacher(tid int,tname varchar(10),addr varchar(20),sub varchar(10))";
                        if(mysqli_query($link,$sql))
                        {
                                                echo"Table created Successfully";
                        }
                        else
                        {
                                    echo"Unable to perform";
                        }
            }
    if($ch=='2')
    {
                        if(!$link)
                        {
                                    die('connection faild:'.mysql_error());
                        }
                                               
                                    $sql="insert into teacher values('102','Prof.Bhilare','Malegaon','PHP')";
                        if(mysqli_query($link,$sql))
                        {
                                    echo"Row inserted Successfully";
                        }
                        else
                        {
                                    echo"Unable to perform";
                        }
            }
            if($ch=='3')
            {
                        if(!$link)
                        {
                                    die('connection faild:'.mysql_error());
                        }
                                               
                                    $sql="update teacher SET addr='Baramati' where tid='101'";
                        if(mysqli_query($link,$sql))
                        {
                                    echo"Record Updated Successfully";
                        }
                        else
                        {
                                    echo"Unable to perform";
                        }
            }
    if($ch=='4')
    {
                        if(!$link)
                        {
                                    die('connection faild:'.mysql_error());
                        }
                                    $sql="delete from teacher where tid='101'";
                        if(mysqli_query($link,$sql))
                        {
                                    echo"Record Deleted Successfully";
                        }
                        else
                        {
                                    echo"Unable to perform";
                        }
    }
}
mysqli_close($link);
?>
</BODY>

</HTML>