Submitting multiple checkbox values in HTML form - php

Question

I have a html form which displays the contents of a mySQL table called banner, containg multiple banner elements, that appear like:
Im using PHP Codeigniter. I want users to be able to update the display checkbox and submit, storing the values 1 and 0 in the database for checked / not.
FormView
<td>
<input type="checkbox" name="bdisplay[]" value="<?php $bannerId?>" <?php if ($displaycheck==1): ?> checked <?php endif;?>>
<?php echo $banner->bdisplay; ?>
</td>
The function for form submission. It creates a new associative array, if checkbox ticked id=>1 or else id=>0.
public function do_updatedisp()
{
$results = array();
foreach($_POST['bdisplay'] as $onedisplay)
{
if(!empty($onedisplay))
{
array_push($results, $results[$onedisplay]=1);
}
else
{
array_push($results, $results[$onedisplay]=0);
}
$this->bannerM->form_update($results);
}
}
The banner model:
function form_update($results)
{
foreach($results as $result=>$value)
{
$this->db->set('bdisplay', $value);
$this->db->where('banner_id', $result);
$this->db->insert('banner');
}
}
This is the error I get:
Cannot add or update a child row: a foreign key constraint fails (vigilantx.banner, CONSTRAINT FK__usarios FOREIGN KEY (user_id) REFERENCES usarios (user_id))
I know there is nothing wrong with the foreign key, there is error elsewhere but
I have been stuck on this for far too long! Any help appreciated!

Answer 1

i'm not sure but i think the problem is the insert method because everytime a user clicks on this checkbox he inserts a new row to your table which could be problematic (don't know your db schema but i think thats causing the foreign key troubles)
try this instead
function form_update($results)
{
foreach($results as $result=>$value)
{
$this->db->set('bdisplay', $value);
$this->db->where('banner_id', $result);
$this->db->update('banner');
}
}

Answer 2

I guess you are making things a big complicated for yourself, you are doing things correctly but doing too much. Basically the value you have implemented the form is correct, for instance you form with checkbox
display banner
when a form is submitted irrespective of any HTTP method being used, on server side only set values are passed therefore on php side if the checkbox is not checked then it will not be present to PHP runtime therefore if you simply check.
<?php
// using HTTP get method
// default value for banner display is zero
$banner_display = 0;
if(isset($_GET['bdisplay'])
$banner_display = 1;
// further write code to do whatever processing you would like to do
?>
The above code works in case you simply have a single checkbox which is optional to user furthermore using just if statement is a optimal way of writing code which help in generating extra branching instructions