storagea.php

<?php
$mysqli = new mysqli('localhost', 'root', '', 'tws');
$link = mysqli_connect("localhost", "root", "", "tws");
$query2 = $mysqli->query("SELECT * FROM `data`");
while ($array2[] = $query2->fetch_object());
array_pop($array2);
$ops = $_POST["ops"];
$ops =explode(" ",$ops);

if($array2[1]->curdata>$array2[2]->curdata){
    $x=$array2[1]->storage-1;
    $n=$array2[2]->storage-1;
}else{
    $x=$array2[2]->storage-1;
    $n=$array2[1]->storage-1;
}
if($ops[0]==="-"){
    if($ops[1]<=($array2[0]->curdata-$array2[0]->minval)){

        $quer = $array2[0]->curdata-$ops[1];
        $sql = "UPDATE `data` SET `curdata` = '$quer' WHERE `data`.`storage` = '1'";

        if(mysqli_query($link, $sql)){
            echo "Records added successfully.";
        }else{
            echo "ERROR: Could not able to execute $sql. " . mysqli_error($link);
        }

    }else if($ops[1]>($array2[0]->curdata-$array2[0]->minval)){
        $y=abs($array2[0]->curdata-$ops[1]);
        $quer = $array2[0]->minval;
        $quer2 = $array2[$x]->curdata-($array2[0]->minval-$y);
        $quer3 = $x+1;
        $sql = "UPDATE `data` SET `curdata` = '$quer' WHERE `data`.`storage` = '1'";
        $sql2 = "UPDATE `data` SET `curdata` = '$quer2' WHERE `data`.`storage` = '$quer3'";

        if(mysqli_query($link, $sql)&&mysqli_query($link, $sql2)){
            echo "Records added successfully.";
        }else{
            echo "ERROR: Could not able to execute $sql. " . mysqli_error($link);
        }
    }

}else if($ops[0]==="+"){
    if(($ops[1]+$array2[0]->curdata)<=$array2[0]->maxval){
        $quer = $ops[1]+$array2[0]->curdata;
        $sql = "UPDATE `data` SET `curdata` = '$quer' WHERE `data`.`storage` = '1'";

        if(mysqli_query($link, $sql)){
            echo "Records added successfully.";
        }else{
            echo "ERROR: Could not able to execute $sql. " . mysqli_error($link);
        }


    }else if(($ops[1]+$array2[0]->curdata)>$array2[0]->maxval){
        $y=abs(($array2[0]->curdata+$ops[1])-$array2[0]->maxval);
        $quer = $array2[0]->maxval;
        $quer2 = $array2[$n]->curdata+$y;
        $quer3 = $n+1;
        $sql = "UPDATE `data` SET `curdata` = '$quer' WHERE `data`.`storage` = '1'";
        $sql2 = "UPDATE `data` SET `curdata` = '$quer2' WHERE `data`.`storage` = '$quer3'";

        if(mysqli_query($link, $sql)&&mysqli_query($link, $sql2)){
            echo "Records added successfully.";
        }else{
            echo "ERROR: Could not able to execute $sql. " . mysqli_error($link);
        }

    }
}else{
    echo "WRONG OPERATION";
}
  header('Location: index.php');

?>