如何通过WP_Query获取LearnDash已发布课程及其子主题

Hey there! Let's tackle this LearnDash course and topic listing issue together. I know exactly how to pull in those sub-topics for each published course—here's what you need to know:

How LearnDash Links Courses to Sub-Topics #

LearnDash stores the relationship between a course (sfwd-courses) and its sub-topics (sfwd-topic) using a post meta field on each topic. Specifically, every topic has a meta key course_id whose value is the post ID of its parent course. That's the key to connecting the two!

Updated Code to List Courses + Their Sub-Topics #

I've expanded your existing code to include a nested query for each course's published topics. This will output each course along with its associated sub-topics in the order you set in the LearnDash Course Builder:

// Query for all published LearnDash courses
$course_args = array(
    'post_type'      => 'sfwd-courses',
    'post_status'    => 'publish',
    'order'          => 'DESC',
    'orderby'        => 'ID',
    'mycourses'      => false,
    'posts_per_page' => -1 // Show all courses; adjust this if you need pagination
);
$course_loop = new WP_Query( $course_args );

// Check if we have courses to display
if ( $course_loop->have_posts() ) :
    while ( $course_loop->have_posts() ) : $course_loop->the_post();
        // Output course details (customize this to match your site's layout)
        echo '<div class="ld-course">';
        echo '<h2>' . get_the_title() . '</h2>';
        echo '<p>' . get_the_excerpt() . '</p>';

        // Query for this course's published sub-topics
        $topic_args = array(
            'post_type'      => 'sfwd-topic',
            'post_status'    => 'publish',
            'order'          => 'ASC',
            'orderby'        => 'menu_order', // Matches the order set in LearnDash Course Builder
            'posts_per_page' => -1,
            'meta_query'     => array(
                array(
                    'key'     => 'course_id', // Meta key linking topic to its parent course
                    'value'   => get_the_ID(), // Current course's post ID
                    'compare' => '='
                )
            )
        );
        $topic_loop = new WP_Query( $topic_args );

        // Output the list of sub-topics
        if ( $topic_loop->have_posts() ) :
            echo '<h3>Course Topics</h3>';
            echo '<ul class="ld-topics">';
            while ( $topic_loop->have_posts() ) : $topic_loop->the_post();
                echo '<li><a href="' . get_permalink() . '">' . get_the_title() . '</a></li>';
            endwhile;
            echo '</ul>';
        else :
            echo '<p>No topics have been added to this course yet.</p>';
        endif;

        echo '</div>';
        // Reset post data for the topic loop to avoid conflicts
        wp_reset_postdata();
    endwhile;
else :
    echo '<p>No published courses are available at this time.</p>';
endif;

// Reset post data for the course loop
wp_reset_postdata();

Key Notes About the Code #

• meta_query: This is the critical part that filters topics to only those associated with the current course. We're matching the course_id meta value to the current course's ID.
• orderby => menu_order: This ensures topics appear in the same order you arranged them in the LearnDash Course Builder. If you prefer ordering by ID, title, or date, you can swap this value.
• wp_reset_postdata(): Always call this after each loop to reset the global post object—this prevents weird behavior with subsequent queries on the page.

内容的提问来源于stack exchange，提问作者Tommy Adeniyi