Recently I needed to view all posts that were password-protected. Not finding a WordPress function for this, I wrote a quick SQL command to find all password-protected posts in the WordPress database.
SELECT * FROM `wp_posts` WHERE `post_password` != ''
As written, this command will select all password-protected posts from the
wp_posts table. Don’t forget to change the
wp_ prefix if your WordPress tables are using something other than the default value.