Checkboxes are checking out randomly

问题

I've got a question.

I've got a page with hundreds of checkboxes wich are generated with the Database. So when the database returns 1 it is checked otherwise it is 0 and not checked. When I try to check the checkbox and try to update that into the database, some checkboxes are randomly checking out..

Code:

This is the Query

if(isset($_POST['submit'])){
                foreach ($_POST['untrain[{$room->room_id}]'] as $room_id) {
                    // This query needs protection from SQL Injection!
                    $user_id;
                    $room_id;
                $untrainQuery = "UPDATE room_users SET trained = '1'  WHERE room_id = $room_id";
                $db->update($untrainQuery);

                }

                }

These are the checkboxes:

<?php
if ($room->trained == 1) {
?> <input type='checkbox' value="<?php
    echo $room->user_id;
?>" name="trained[<?php
    echo $room->room_id;
?>]" checked> <?php
    echo "Y";
} else if ($room->trained == 0) {
?> <input type='checkbox' value="<?php
    echo $room->user_id;
?>" name="untrain[<?php
    echo $room->room_id;
?>]"> <?php
    echo "N";
}
?> </td>
                    <Td><?php
if ($room->active == 1) {
?> <input type='checkbox' name="<?php
    echo $room->room_id;
?>" checked> <?php
    echo "Active";
} else {
?> <input type='checkbox' name="<?php
    echo $room->room_id;
?>"  <?php
    echo "Inactive";
}
?>

So when the database returns 1 the checkbox is checked otherwise it is 0 so unchecked.. So my question is why it is randomly checking out checkboxes?

I want to check the checkboxes to update the database with 1, but sometimes it randomly checking out checkboxes?!

回答1:

Your logic has the following flaws: your $_POST array has the key untrain and its value is an internal array of keys room_id (because they are in the checkbox name) and values user_id (checkbox's values). In your foreach loop $room_id has assingned the values of checkboxes, which are indeed user_ids. Besides you should iterate over $_POST['untrain'], I don't know where you take that key $room->room_id from.

I would change that to:

if(isset($_POST['submit'])){
    foreach ($_POST['untrain'] as $room_id => $user_id) {
        //sanitize $room_id
        $untrainQuery = "UPDATE room_users SET trained = '1'  WHERE room_id = $room_id";
        $db->update($untrainQuery);
    }
}

Or, if you have an array of all room_ids, you can iterate over them to check if which are checked:

if(isset($_POST['submit'])){
    foreach ($room_ids as $room_id) {
        //sanitize $room_id
        if(isset($_POST["untrain[{$room_id}]"]){//that is, if it was checked
            $trained = 1;
        }else{
            $trained = 0;
        }
        $untrainQuery = "UPDATE room_users SET trained = $trained  WHERE room_id = $room_id";
        $db->update($untrainQuery);
    }
}

来源：https://stackoverflow.com/questions/29486911/checkboxes-are-checking-out-randomly

标签

php

mysql

sql

checkbox

mysqli