In order to get the commission for each employ we first have to generate a database and its tables. CREATE TABLE Employee( EmpNumber int not null, EmpFirstName varchar(100) not null, EmpLastName varchar(100) not null, CommissionRate decimal(3,2) not null, YrlySalary int not null, DepartmentID int, JobID int, PRIMARY KEY (EmpNumber), FOREIGN KEY (DepartmentID) references Department(DepartmentID), FOREIGN KEY (JobID) references Job(JobID) ).
CREATE TABLE Job( JobID int not null, JobDescription varchar(400) not null, PRIMARY KEY (JobID) )
CREATE TABLE Department( DepartmentID int not null, DepartmentDescription varchar(400) not null, PRIMARY KEY(DepartmentID) )
CREATE TABLE Invoice (InvNumber int not null, InvDate date, EmpNumber int, InvAmount int not null, PRIMARY KEY (InvNumber), FOREIGN ...