创建yggl数据库上的视图Employees_view,视图包含员工号码、姓名和实际收入。相关知识点: 试题来源: 解析 create or replace view Employees_view(EmployeeID,Name,RealIncome) as select Employees.EmployeeID,Name,InCome-OutCome from Employees,Salary where Employees.EmployeeID=Salary.EmployeeID;...