单项选择题
假设Employee表有三列EmpIEmpGrade、EmpSalaryGrade,并且列值都是整型数据类型,则以下( )中的语句能正确执行。
A.SELECT EmpID FROM Employee ORDER BY EmpID WHERE EmpID=EmpGrade;
B.SELECT EmpID FROM Employee WHERE EmpID=EmpGrade=EmpSalaryGrade;
C.SELECT EmpID FROM Employee ORDER BY EmpGrade+EmpSalaryGrade;
D.SELECT EmpID,EmpGrade FROM Employee WHERE EmpGrade+EmpSalaryGrade;