学渣刚碰SQL，学了几个礼拜，却仍不会做练习！只会简单SELECT, FROM, WHERE...  跪求求大神帮忙，万分感激！！！

这个是数据结构的版块，下次换sql版块问吧
1.1，select e.ename from aircraft a,certified c,employeess e where a.aid=c.aid and e.eid=c.eid and a.aname='Boeing'