get_results("SELECT * FROM $wpdb->usermeta"); foreach ($allUserMeta as $userMeta) { $found = strpos ( $userMeta->meta_key , 'custom_field_' ); if ( $found !== FALSE ){ $metaFieldName = $userMeta->meta_key; $metaFieldValue = $userMeta->meta_value; $wpdb->query("DELETE FROM $wpdb->usermeta WHERE meta_key = '".$metaFieldName."' AND meta_value = '".$metaFieldValue."'"); } $foundAvatar = strpos ( $userMeta->meta_key , 'custom_field_resized' ); if ( $foundAvatar !== FALSE ){ $metaFieldName = $userMeta->meta_key; $metaFieldValue = $userMeta->meta_value; $wpdb->query("DELETE FROM $wpdb->usermeta WHERE meta_key = '".$metaFieldName."' AND meta_value = '".$metaFieldValue."'"); } }