刚学数据库，遇到一道关于数据库sql语句的题目，实在不会，请高手帮忙解答一下，谢谢！

(1) SELECT Ename, Dnumber, Salary FROM EMPLOYEE JOIN (SELECT Dnumber, avg(Salary) AS Asalary FROM EMPLOYEE GROUP BY Dnumber) A ON Dnumber = A.Dnumber WHERE Salary > A.Asalary ORDER BY Dnumber （2） SELECT Ename FROM EMPLOYEE JOIN (SELECT ES