check correctly checkboxes from mysql (php) - php

Question

I have a problem with checkboxes.
I have some project they you can filter at categories.
So the problem is when you want edit a project that automatic the correct category are checked.
here you see a project but the categories are empty
In mine databank I use is a combo table - one to insert my categories and one for the project and there I have a combo table from.
Here you see my code for display the checkboxes and select for editing so now I looking for some help, for checked the correctly checkbox that belongs to that project.
<div id="categoriefilter">
<?php
$sql = "SELECT * FROM `categories` ORDER BY `id` ASC";
$cats = DB::getResult($sql);
foreach($cats as $cat){
?>
<label>
<input name="cat[]" type="checkbox" value="<?php echo $cat['id']; ?>" >
<?php echo $cat['categorienaam']; ?>
</label>
<?php
}
?>
</div>

Answer 1

If I understand your question correctly. You need 3 tables here
Table1 : projects id, name, ...
Table2: categories id, name, ...
Table3: projects_categories project_id, category_id, ...
The third table is needed to store the categories which are selected for projects
And inside your project page
You need to do the followings:
Select your project by its id
Select categories
Select categories related to the project ( from Table3 )
Here is example ( this is not a working code, just a showcase )
// your project
$project = DB::getResult("SELECT * FROM project WHERE id = :id "); // <== id here
// list of categories
$categories = DB::getResult("SELECT * FROM categories ");
// list of categories for this project
$project_categories = DB::getResult("SELECT category_id FROM projects_categories WHERE project_id = :project_id ");
$project_categories = (array) $project_categories; // in case DB::getResult is not array
<?php
foreach($categories as $category) :
?>
<label>
<input name="cat[]"
<?php if(in_array($category['id'], $project_categories)) echo 'checked="checked"'; ?>
type="checkbox" value="<?= $category['id']; ?>" >
<?php echo $category['name']; ?>
</label>
<?php endforeach; ?>

Answer 2

I'm not down voter. If you knew your problem, you probably mightn't post the question.
You don't include the details code. However for the part as far as I'm understanding,
You should run database UPDATE query inside foreach loop. You don't need to keep the html input inside the loop.
<?php
// check if checkbox is checked
if (!empty($_POST['cat'])){
foreach($_POST['cat'] as $cat){
// run update query here
$sql = "UPDATE `categories` SET `categorienaam` = $whatever WHERE `id` = $cat";
$result = DB::getResult($sql);
}
}
?>
<label>
<input name="cat[]" type="checkbox" value="<?php echo $RowOfApplicableSelectQuery['id']; ?>" >
</label>
$RowOfApplicableSelectQuery comes from the query that you are using to fetch and display your record primarily.
I hope it gives you a clue about what are you looking for.