SQL数据库作业，补考要求教份作业大家帮忙了！！

1.select a.*,b.*,c.* from emp a,orz b,dep c where b.eno=a.eno and c.dno=a.dno
2.select name,sal from emp where age > '55'
3.select a.sal,b.job from emp a,orz b where a.age>'45' and a.age<'55' and b.eno=a.eno
4.select a.name b.wok,b.job from emp a,orz b where a.eno=b.eno and not(b.wok='经理')
5.select a.name,b.wok,b.job from emp a,orz b where a.eno=b.eno and a.dno in (select c.dno from dep c where c.num in(select count(d.*) from emp d where d.sal>'2000'))
6.select count(a.sal) from emp a,orz b where a.eno=b.eno and b.wok='经理' or b.wor='主管'
7.select max(a.sal) from emp a,orz b where a.eno=b.eno and b.wok='经理' or b.wor='主管'