在PHP中填充类别匹配表中的复选框

Question

I have a list of categories associated with a post in a database. Here is an example of what the categories look like in the database (PID = PostID and CATID = Category ID).

PID   CATID
 1      34
 1      12
 1      15

I have a php form that displays a list of all categories next to an array of checkboxes using name = "catid[]". I need to know the best practice to query the database and and write PHP code so that it pre-check the boxes for categories 12, 15, and 34 using the CHECKED attribute in each appropriate form checkbox for the POST with an PID of 1.

Here is the function that produces the list of categories.

function categoryTree($pid, $cat_type, $parentid = 0, $sub_mark = ''){
global $db;

$query = $db->query("SELECT * FROM categories WHERE parentid = $parentid and cat_type = '$cat_type' ORDER BY parentid, category ASC");

if($query->num_rows > 0){
    while($row = $query->fetch_assoc()){
        if ($row['parentid'] == 0) {
            echo '<div><label><span class="font-md">'.$sub_mark.$row['category']."</span></label></div>";
        } else {
            echo '<div class="checkbox" style="padding-left:15px;padding-top:5px;padding-bottom:5px;"><label><input name="catid[]" type="checkbox" value="'.$row['catid'].'" class="checkbox style-0"><span>'.$sub_mark.$row['category']."</span></label></div>";
        }
        categoryTree($cat_type, $row['catid'], $sub_mark.' ');
    }
    }
}

Thanks in advance.

Answer 1

Assuming you have the array of checked categories ids as $checkedCategories you could do something like this.

<?php foreach ($categories as $category) : ?>
   <input name="catid[]" 
       value="<?php echo $category['id']; ?>" 
       <?php echo in_array($category['id'], $checkedCategories)? 'checked':'' ?>>
   <?php echo $category['name']; ?>
   <br>
<?php endforeach; ?>