WordPress database error: [COLLATION 'utf8mb4_unicode_520_ci' is not valid for CHARACTER SET 'utf8']SELECT g.*, GROUP_CONCAT(COALESCE(wp.ID, ug.user_id)) AS users, GROUP_CONCAT(CASE WHEN ug.is_trainer = 1 THEN COALESCE(wp.ID, ug.user_id) ELSE NULL END) AS trainers FROM wp_nkg3n3b9pd_cluevo_user_groups g
LEFT JOIN wp_nkg3n3b9pd_cluevo_users_to_groups ug ON g.group_id = ug.group_id
LEFT JOIN wp_nkg3n3b9pd_users wp ON LOCATE('@', g.group_name) AND wp.user_email COLLATE utf8mb4_unicode_520_ci RLIKE g.group_name GROUP BY g.group_id
