checked values for the SELECT: WHERE clause - php

Question

I am trying to create a compare option between selected cars.
<?php
if(isset($_POST['compares'])) {
$id_nums = array($_POST['cBox']);
//$id_nums = array(1,6,12,18,24);
$id_nums1 = implode(", ", $id_nums);
$query = "SELECT * FROM wp_cars WHERE id in ($id_nums1)";
$cCars = mysql_query($query) or mysql_error();
while($car = mysql_fetch_array($cCars)) {
echo $car['cartitle']."<br/>";
echo $car['saleprice']."<br/>";
}
} else {
$query1 = "SELECT * FROM wp_cars";
$allcars = mysql_query($query1) or die(mysql_error()); `
while($car1 = mysql_fetch_array($allcars)) {
echo "<input type='checkbox' value=".$car1['id']." name='cBox[]' />";
echo $car1['cartitle']."<br/>";
echo $car1['saleprice']."<br/>";
}
}
?>
How to pass the checkbox name(cBox[]) array based on checkboxes selection.
<form action="compares.php" method="post">
<button name="compares">Select Cars to Compare</button>
</form>

Answer 1

$id_nums = array($_POST['cBox']);
$_POST['cBox'] is already an array, you are making a 2d array. Doing
$id_nums1 = implode(", ", $_POST['cBox']);
would do what you want. Although it is wide open to SQL injection.

Answer 2

From your HTML part, send inputs this way:
<form action="compares.php" method="post">
<?php foreach (mysql_fetch_array($allcars) as $car: ?>
<input type="checkbox" value="<?php echo $car['id']; ?>" name="cBox[]" />
<?php echo $car['cartitle']; ?><br />
<?php echo $car['saleprice']; ?><br />
<?php endforeach; ?>
</form>
And in your PHP part, receive inputs this way:
$id_nums = implode(",", $_POST['cBox']);