mysql - 加入MYSQL查询问题

Question

上面是我的查询...但是 observer_ID 和 staff_ID 的对应名称在另一个名为 staff 的表中。所以我需要如何加入 (o.observer_ID=s.staff_ID) 和 (o.staff_ID=s.staff_ID) 以获得观察者和被观察者的两个名字 (o.staff_ID)。请帮助我。谢谢

SELECT DISTINCT o.Room, o.Date,o.Module_code,o.observer_ID,o.staff_ID,o.form_id
FROM mbm2_db.observation_details as o,mbm2_db.Staff as s
WHERE o.date = '2011-08-09' and o.Module_code = 'IS5103'

Answer 1

SELECT DISTINCT 
    o.Room, o.Date,o.Module_code,o.observer_ID,o.staff_ID,o.form_id,
    s1.name, s2.name
FROM 
    mbm2_db.observation_details AS o
    LEFT JOIN mbm2_db.Staff AS s1 ON o.observer_ID = s1.staff_ID
    LEFT JOIN mbm2_db.Staff AS s2 ON o.staff_ID = s2.staff_ID
WHERE 
    o.date = '2011-08-09' AND o.Module_code = 'IS5103'