仅显示一个子类别的帖子-Wordpress

Question

Assume i have the following categories.

Movies

----- Action
----- Science fiction
----- Drama

Music

----- POP
----- Rock

Here, Movies and Music are the parent categories and rest of them are the subcategories.

If i want to display only the POP music ( posts for POP) from the Music category, How can I do that.

Please Help!.

I have no idea how to display posts from sub-categories. Only thing i have is an example code which can able to display Parent and subcategories posts.

<?
// Get the post ID
        $id = get_the_ID();         


        //get all the categories ( this function will return all categories for a post in an array)
        $category= get_the_category( $id );

        if ($category->category_parent == 0) {

        //extract the first category from the array
        $catID = $category[0]->cat_ID;

        //Assign the category ID into the query
        $verticalNavigationSwitcher = "cat=$catID&orderby=ID&order=ASC";
     }              


        $result = new WP_Query($verticalNavigationSwitcher);


                    //$featuredPosts->query('showposts=5&cat=3');
                    while ($result->have_posts()) : $result->the_post(); 
        ?>


   <li><a href='<?php the_permalink() ?>'><span><?php the_title(); ?></span></a></li>


  <?php 
            endwhile; 
            wp_reset_postdata();
 ?> 

Answer 1

It looks like the example you are using over complicates things. If you simply need the posts from a particular category then you can use either the category slug or ID to retrieve the posts, and use WP_Query as in the above example.

So if the 'Pop' category has an id of 4 (you can get the category ID by hovering over the category name in Posts -> Categories...it's shown in the edit link) then your code would be;

<?php
$result = new WP_Query( 'cat=4' );

while ($result->have_posts()) : $result->the_post(); 
?>

Here's the relevant section from the Codex;

https://codex.wordpress.org/Class_Reference/WP_Query#Category_Parameters

Answer 2

I have found a way to show only one sub-category posts.

if I use "category__in" in my query, it is returning one category posts.

$verticalNavigationSwitcher = "category__in=$catID&orderby=ID&order=ASC";