If checkbox is checked then insert to database - php

Question

I want to insert into my mysql database only those rows that have a checked checkbox at the end.
Since i have several tables and table data cells that have the same name, then my data is stored in arrays (product_name[] etc.):
<form action="<?php echo $_SERVER['PHP_SELF'];?>" method="post">
<?php
while($res = mysqli_fetch_array($result)) {
echo "<table id='tbl'>
<thead><th name='category[]'>".$res['category_name']."</th></thead>
<tbody>
<tr>
<td><input name='product_name[]' id='name' type='text'></td>
<td><input name='quantity[]' type='text' value='1'></td>
<td><input type='checkbox' name='check[]'></td>
</tr>
</tbody>";
}
?>
</table>
<div class="bottom-btn">
<button id="submit" type="submit">Lisa märgitud külmkappi</button>
</div>
</form>
Do i have to store the checkboxes in array as well (check[])?
My php code for the insert:
if ($_SERVER["REQUEST_METHOD"] == "POST") {
$product_name = $_POST['product_name'];
$quantity = $_POST['quantity'];
// $check = $_POST['check'];
foreach($product_name as $i=>$product_name)
{if(!empty($product_name)){
$sql = "INSERT INTO products (id, product_name, category, quantity, expiration_date, barcode) VALUES ('','$product_name', '', '$quantity[$i]', '', '')";
if($stmt = mysqli_prepare($conn, $sql)){
mysqli_stmt_bind_param($stmt, "ss",$param_product_name, $param_quantity);
$param_product_name = $product_name;
$param_quantity=$quantity;
if(mysqli_stmt_execute($stmt)){
header("location: myFridge.php");
} else{
echo "Something went wrong. Please try again later.";
}
mysqli_stmt_close($stmt);
}
}
}
mysqli_close($conn);
}
So far i have tried this: if(!empty($_POST['check'])) and this if(isset($_POST['check']) , but those did not work.
How to check if checkbox is checked before inserting data to database?
EDIT. WORKING.
I added this code to my page to make an array of checkbox on and off values:
function getAllCheckboxValues($check){
$found = array();
foreach ($check as $key => $val){
if($val == 'on'){
$found[] = $key;
}
}
foreach($found as $kev_f => $val_f){
unset($check[$val_f-1]);
}
$final_arr = array();
return $final_arr = array_values($check);
}
$checkbox_arr = getAllCheckboxValues($_POST['check']);
And also added a hidden input before every checkbox:
<input type='hidden' name='check[]' value='off'>
Then matched the checbox array with my products array and voila!

Answer 1

You could simply var_dump($_POST) to see whats in your post request. That always helps when facing issues like that.
Checkboxes come with the value on if they are checked and off if they are not, so it will never be empty and always be set, which is why your checks did not work. You should check if($_POST['check'] === 'on') instead.