单项选择题
A.The underlying tables must have data.
B.You need SELECT privileges on the view.
C.The underlying tables must be in the same schema.
D.You need SELECT privileges only on the underlying tables.
单项选择题 You need to create a view EMP_VU. The view should allow the users tomanipulate the records of only the employees that are working for departments 10 or 20. Which SQL statement would you use to create the view EMP_VU?（）
单项选择题 Evaluate this SQL statement: SELECT e.employee_id, (.15* e.salary) + (.5 * e.commission_pct) + (s.sales_amount * (.35 * e.bonus)) AS CALC_VALUE FROM employees e, sales s WHERE e.employee_id = s.emp_id; What will happen if you remove all the parentheses from the calculation?（）
单项选择题 Click the Exhibit button to examine the structures of the EMPLOYEES and TAX tables. You need to find the percentage tax applicable for each employee. Which SQL statement would you use?（）