<?php
    $con=mysqli_connect("localhost","root","","krishnadatabase");
    $msg="";
    
    if(isset($_POST["b1"]))
    {
        $s1=$_POST["t1"];
        $s2=$_POST["t2"];
        $s3=$_POST["t3"];
        $s4=$_POST["t4"];
        mysqli_query($con,"Insert into Students values($s1,'$s2','$s3',$s4)");
        $msg="Data Inserted Successfully!";
        
    }
    $ss1="";
    $ss2="";
    $ss3="";
    $ss4="";
    if(isset($_POST["b2"]))
    {
          $s1=$_POST["t1"];
          $res=mysqli_query($con,"Select * from Students where RollNo=$s1");
          if($row=mysqli_fetch_row($res))
          {
            $ss1=$row[0];
            $ss2=$row[1];
            $ss3=$row[2];
            $ss4=$row[3];
            $msg="Data Is Found Successfully!";
          }
          else
          {
            $msg="Data Is Not Found !";
          }
        
    }
    if(isset($_POST["b3"]))
    {
        $s1=$_POST["t1"];
        $s2=$_POST["t2"];
        $s3=$_POST["t3"];
        $s4=$_POST["t4"];
        mysqli_query($con,"Update Students set Name='$s2', Course='$s3', Age=$s4 where RollNo=$s1");
        $msg="Data Updated Successfully!";
    }
    if(isset($_POST["b4"]))
    {
        $s1=$_POST["t1"];
        $s2=$_POST["t2"];
        $s3=$_POST["t3"];
        $s4=$_POST["t4"];
        mysqli_query($con,"Delete from Students where RollNo=$s1");
        $msg="Data Deleted Successfully!";
    }
    if(isset($_POST["b5"]))
    {
        header("location:show_all_data.php");
    }
         
          
?>

<html>
    <head>

    </head>
    <body>
        <form method='post'>
            <table align='center'>
                <tr><td>Database :</td><td>krishnadatabase</td></tr>
                <tr><td>Table :</td><td>Students</td></tr>
                <tr><td>Student RollNo :</td><td><input type='text' name='t1' value='<?=$ss1;?>'></td></tr>
                <tr><td>Student Name :</td><td><input type='text' name='t2' value='<?=$ss2;?>'></td></tr>
                <tr><td>Student Course :</td><td><input type='text' name='t3' value='<?=$ss3;?>'></td></tr>
                <tr><td>Student Age :</td><td><input type='text' name='t4' value='<?=$ss4;?>'></td></tr>
                <tr><td></td><td><input type='submit' name='b1' value='Insert'> <input type='submit' name='b2' value='Search'></td></tr>
                <tr><td></td><td><input type='submit' name='b3' value='Update'> <input type='submit' name='b4' value='Delete'></td></tr>
                <tr><td></td><td><input type='submit' name='b5' value='Show all Data'></td></tr>
                <tr><td></td><td><?=$msg;?></td></tr>

            </table>
        </form>
        
    </body>
</html>