WordPress：统计指定用户所有文章的自定义meta_value总和

Got it, let's sort this out for you! Your original code counts how many posts have the _heart_this meta key, but we need to calculate the sum of all the numeric meta values instead. Here are two solid approaches:

Option 1: Efficient Database Query (Recommended) #

Using $wpdb directly is the fastest way, since we don't need to load full post objects—we just need an aggregated sum.

global $wpdb;

$target_user_id = 1; // The user ID you're targeting
$total_heart_sum = $wpdb->get_var(
    $wpdb->prepare(
        "SELECT SUM(pm.meta_value)
         FROM {$wpdb->postmeta} pm
         INNER JOIN {$wpdb->posts} p ON pm.post_id = p.ID
         WHERE pm.meta_key = %s
         AND p.post_author = %d
         AND p.post_status = 'publish' // Optional: exclude drafts/private posts
         AND pm.meta_value REGEXP '^[0-9]+$'", // Ensure we only sum numeric values
        '_heart_this',
        $target_user_id
    )
);

// Output the sum, default to 0 if no matching posts exist
echo $total_heart_sum ? $total_heart_sum : 0;

Why this works: #

• The INNER JOIN ensures we only count posts that actually belong to the target user (avoids orphaned postmeta entries).
• REGEXP '^[0-9]+$' filters out any non-numeric meta values, so you don't get weird results from invalid data.
• $wpdb->prepare() keeps your query safe from SQL injection—always use this when adding variables to database queries!

Option 2: Using WP_Query (More Intuitive for Beginners) #

If you prefer working with WordPress' native query system, you can loop through matching posts and accumulate the values:

$user_posts = new WP_Query([
    'meta_key' => '_heart_this',
    'author' => 1,
    'posts_per_page' => -1, // Fetch all matching posts
    'post_status' => 'publish' // Optional: limit to published posts
]);

$total_heart_sum = 0;

if ($user_posts->have_posts()) {
    while ($user_posts->have_posts()) {
        $user_posts->the_post();
        $heart_value = get_post_meta(get_the_ID(), '_heart_this', true);
        
        // Only add to the sum if the value is a number
        if (is_numeric($heart_value)) {
            $total_heart_sum += intval($heart_value);
        }
    }
    wp_reset_postdata(); // Critical: reset the global post data after the loop
}

echo $total_heart_sum;

Note on performance: #

This method is fine for small post counts, but if the user has hundreds or thousands of posts, the direct $wpdb query will be much faster since it avoids loading all post objects into memory.

内容的提问来源于stack exchange，提问作者robert0