Article management - Category, subcategory - Checkbox

[pospan]

Hello Community,
 
I have some diffuclties about getting the right logic for article management with subcategories. So everything with Categorys is fine.
 
TABLE: articles    
articleID
    title
    content
    cat_relatedID
 
TABLE: categories 
    catID
    cat_name
 
On submit it Works fine where in "selection option" I can select the Category for that post. Now I want to extend it with subcategories.
 
TABLE: articles      
    articleID
    title
    content
    cat_relatedID
 
TABLE: categories     
    catID
    cat_name
 
TABLE: subcategories 
    subcatID
    subcat_name
    related_catID
 
Now the problem is how to relate Cats and Subcats in the form where I am adding new Articles and submit it to mysql. Do I need a additional field in the article table subcatID or anything else? My logic is something to make like in Wordpress when adding New posts you have the option to check categories related with that post. 
 
 

    <ul class="list-unstyled categorychecklist ">
        <li><input type="checkbox" value=""> Category 1
            <ul class="children">
                <li><input type="checkbox" value=""> Subcategory 1</li>
                <li><input type="checkbox" value=""> Subcategory 2</li>
                <li><input type="checkbox" value=""> Subcategory 3</li>
            </ul>        
        </li>    
        <li><input type="checkbox" value=""> Category 2
            <ul class="children">
                <li><input type="checkbox" value=""> Subcategory 4</li>
                <li><input type="checkbox" value=""> Subcategory 5</li>
                <li><input type="checkbox" value=""> Subcategory 6</li>
            </ul>        
        </li>
        <li><input type="checkbox" value=""> Category 3 - No subcategories</li>
    </ul>  

 LINK should look something like this example:

 mylink.com/category.php?ID=12&sub_ID=15

 

Image attached is how it looks now.

[Barand]

Easiest way is to store all in the category table. The parent id of of top-level categories will be NULL, in subcats it's the id of the parent category

TABLE: articles                 TABLE: categories 

    articleID         +------      catID         ---+
    title             |            cat_name         |
    content           |            parentCatID   >--+
    catID       >-----+