PHP_Script_for_getting_Year_of_ENG_Student

<?php
$servername = "localhost";
$username = "root";
$password = "";
$dbname = "registration";
$conn = new mysqli($servername, $username, $password, $dbname);

//Create Connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}

$sql = "SELECT id,year FROM student";
$result = $conn->query($sql);


if (mysqli_num_rows($result) > 0)
{
    // output data of each row
    $rowcount=mysqli_num_rows($result);
    while($array = mysqli_fetch_assoc($result))
    {
        $mainId[]=$array["id"];
        $mainYear[]=$array["year"];

    }

}
else
{
    echo "0 results";
}
$sub=date('M Y');
echo "\n";
$presentYear=date('Y');   //2018
$presentMon=date('m');    //Sepetember 09
echo $presentMon;
echo $presentYear;

//Calculating present year for all the students
echo $rowcount; //Number of rows in sql result
$row=4;
echo "<br>".$presentYear."<br>";
echo "Main year is ".$mainYear[0]."<br>";


function calcuateonemonth($id)
{


    if($GLOBALS['presentMon']>=06)
    {
        echo "ID having ".$GLOBALS['temp']." is Firstyear <br>";
    }
    else
    {
       echo "ID having ".$GLOBALS['temp']." is Having Error <br>";
    }
}
function calcuatetwomonth($id)
{
    echo $id;
    if($GLOBALS['presentMon']>=06)
    {
        echo "ID having ".$GLOBALS['temp']." is Secondyear <br>";
    }
    else
    {
         echo "ID having ".$GLOBALS['temp']." is Firstyear <br>";
    }
}
function calcuatethreemonth($id)
{

    if($GLOBALS['presentMon']>=06)
    {
      echo "ID having ".$GLOBALS['temp']." is Thirdyear<br>";
    }
    else
    {
        echo "ID having ".$GLOBALS['temp']." is Secondyear<br>";
    }
}
function calcuatefourmonth($id)
{

    if($GLOBALS['presentMon']>=06)
    {
      echo "ID having ".$GLOBALS['temp']." is Fourthyear<br>";
    }
    else
    {
         echo "Thirdyear";
    }

}
function calcuatefifthmonth($id)
{

    if($GLOBALS['presentMon']<06)
    {
       echo "ID having ".$GLOBALS['temp']." is Thirdyear<br>";
    }
    else
    {
            echo "ID having ".$GLOBALS['temp']." is Having Error <br>";
    }
}




for($i=0;$i<$rowcount;$i++)
{
    $temp=$mainId[$i];
   if($presentYear==$mainYear[$i])
   {
      calcuateonemonth($i);
   }
    else if($presentYear==$mainYear[$i]+1)
    {
       calcuatetwomonth($i);
    }
    else if($presentYear==$mainYear[$i]+2)
    {
        calcuatethreemonth($i);
    }
     else if($presentYear==$mainYear[$i]+3)
    {
        calcuatefourmonth($i);
    }
     else if($presentYear==$mainYear[$i]+4)
    {
      calcuatefifthmonth($i);
    }
    else
    {
         echo "ID having ".$GLOBALS['temp']." is Having Error <br>";
    }


}

?>