Где ошибка в sql-коде (запросе)? Запрос в Access.

[Access54321]

SELECT TOP 3 department.parent_id AS Департамент, TOP 3 department.dep_name AS Управление, ROUND(avg(Datediff("yyyy",birthdate ,Date())+(Format(birthdate,"mmdd")> Format(Date(),"mmdd"))),0) AS Средний_возраст
FROM employee
LEFT JOIN department ON employee.dep_id = department.dep_id
GROUP BY department.parent_id, department.dep_name
HAVING department.dep_name IS NULL OR department.dep_name LIKE 'Управление *'
ORDER BY ROUND(avg(Datediff("yyyy",birthdate ,Date())+(Format(birthdate,"mmdd")> Format(Date(),"mmdd"))),0)
UNION
SELECT TOP 3 department.parent_id AS Департамент, TOP 3 department.dep_name AS Управление, ROUND(avg(Datediff("yyyy",birthdate ,Date())+(Format(birthdate,"mmdd")> Format(Date(),"mmdd"))),0) AS Средний_возраст
FROM employee
RIGHT JOIN department ON employee.dep_id = department.dep_id
GROUP BY department.parent_id, department.dep_name
HAVING department.dep_name IS NULL OR department.dep_name LIKE 'Управление *'
ORDER BY ROUND(avg(Datediff("yyyy",birthdate ,Date())+(Format(birthdate,"mmdd")> Format(Date(),"mmdd"))),0);

Задача: выгрузить топ-3 подразделения по среднему возрасту.
Может кто-то помочь без приложенного файла Access?

[evg_m]

SELECT TOP 3 department.parent_id AS Департамент, TOP 3 department.dep_name AS Управление,....

[Access54321]

Сообщение от evg_m

SELECT TOP 3 department.parent_id AS Департамент, TOP 3 department.dep_name AS Управление,....

Думала об этом, пробовала так - не работает все-равно.

Причем, по отдельности вот так работает (см. ниже), но, когда объединяю через UNION LEFT и RIGHT JOINы, - выдает ошибку.

Вот это работает:
SELECT TOP 3 department.parent_id AS Департамент, department.dep_name AS Управление, ROUND(avg(Datediff("yyyy",birthdate ,Date())+(Format(birthdate,"mmdd")> Format(Date(),"mmdd"))),0) AS Средний_возраст
FROM employee
RIGHT JOIN department ON employee.dep_id = department.dep_id
GROUP BY department.parent_id, department.dep_name
ORDER BY ROUND(avg(Datediff("yyyy",birthdate ,Date())+(Format(birthdate,"mmdd")> Format(Date(),"mmdd"))),0) DESC


И вот это работает:
SELECT TOP 3 department.parent_id AS Департамент, department.dep_name AS Управление, ROUND(avg(Datediff("yyyy",birthdate ,Date())+(Format(birthdate,"mmdd")> Format(Date(),"mmdd"))),0) AS Средний_возраст
FROM employee
LEFT JOIN department ON employee.dep_id = department.dep_id
GROUP BY department.parent_id, department.dep_name
ORDER BY ROUND(avg(Datediff("yyyy",birthdate ,Date())+(Format(birthdate,"mmdd")> Format(Date(),"mmdd"))),0) DESC

[evg_m]

order by 3 написать ОДИН раз в конце