De query kan niet uitgevoerd worden. :: SELECT `agenda_data`.*, `page`.*, `agenda_information`.*, DATE_FORMAT(`agenda_data`.`start_date`, '%m') AS maand, DAY(`agenda_data`.`start_date`) AS dag, YEAR(`agenda_data`.`start_date`) AS jaar, DATE_FORMAT(`agenda_data`.`start_date`, '%d-%m-%Y') AS datum, DATE_FORMAT(`agenda_data`.`end_date`, '%d-%m-%Y') AS eind_datum, CONCAT(DATE_FORMAT(`agenda_data`.`start_date`, '%m'),`agenda_data`.`agenda_id`) AS cursus_group FROM `agenda_data`, `page`, `agenda_information`, `agenda_cats` WHERE `page`.`page_id` = `agenda_data`.`agenda_id` AND `agenda_information`.`agenda_id` = `agenda_data`.`agenda_id` AND DATE_FORMAT(NOW(), '%Y %m %d') <= DATE_FORMAT(`agenda_data`.`start_date`, '%Y %m %d') AND NOW() >= `page`.`start_date` AND `page`.`status` >= 3 AND `agenda_data`.agenda_data_id = GROUP BY cursus_group ORDER BY jaar, maand, dag, `agenda_data`.`agenda_id`