What are WordPress orphaned user meta and how to clean them?
User metadata refers to the additional details you provide about each user, which are not typically stored in the WordPress users’ table. Occasionally, some of this metadata can become orphaned, meaning it no longer belongs to any user. These orphaned user meta entries are unnecessary and should be removed.
To clean up these orphaned entries, you have two options: use our Advanced Database Cleaner plugin or run the following SQL code directly through phpMyAdmin (which the plugin uses):
DELETE FROM usermeta WHERE user_id NOT IN (SELECT ID FROM users)