<?php
$link = mysqli_connect("localhost", "root", "himura", "mels");

// Check connection
if($link === false){
    die("ERROR: Could not connect. " . mysqli_connect_error());
}
?>

<form action="" method="post">
<input type="checkbox" name="check_list[]" value="C/C++" <?php echo ( isset($_POST['check_list']) AND in_array( "C/C++", $_POST['check_list'] ) ) ? "checked" : ""; ?>><label>C/C++</label><br/>
<input type="checkbox" name="check_list[]" value="Java" <?php echo ( isset($_POST['check_list']) AND in_array( "Java", $_POST['check_list'] ) ) ? "checked" : ""; ?>><label>Java</label><br/>
<input type="checkbox" name="check_list[]" value="PHP" <?php echo ( isset($_POST['check_list']) AND in_array( "PHP", $_POST['check_list'] ) ) ? "checked" : ""; ?>><label>PHP</label>  <br/>
<input type="submit" name="submit" value="Submit"/>

</form>

<?php

if(isset($_POST['submit']))
{//to run PHP script on submit
    if(!empty($_POST['check_list'])) {
        foreach($_POST['check_list'] as $selected) {
            if($selected!="") {
                $stmt = $link->prepare('INSERT INTO `checkbox` (`php_value`) VALUES (?)');
                $stmt->bind_param('s', $selected);
                $stmt->execute();
                $stmt->close();
            }
        }
        mysqli_close($link);
    }
}


?>