The EMPLOYEES table contains these columns:

You need to write a query that will produce these results:
1. Display the salary multiplied by the commission_pct.
2. Exclude employees with a zero commission_pct.
3. Display a zero for employees with a null commission value.
Evaluate the SQL statement:

What does the statement provide?（）

单项选择题A subquery can be used to（）.

A. Create groups of data
B. Sort data in a specific order
C. Convert data to a different format
D. Retrieve data based on an unknown condition

单项选择题Which clause should you use to exclude group results?（）

A. WHERE
B. HAVING
C. RESTRICT
D. GROUP BY
E. ORDER BY

单项选择题Evaluate these two SQL statements:SELECT last_name, salary, hire_dateFROM EMPLOYEES ORDRE BY salary DESC; SELECT last_name, salary, hire_dateFROM EMPOLYEES ORDER BY 2 DESC; What is true about them?（）

A. The two statements produce identical results.
B. The second statement returns a syntax error.
C. There is no need to specify DESC because the results are sorted in descending order by default.
D. The two statements can be made to produce identical results by adding a column alias for the salary column in the second SQL statement.

单项选择题Which is an iSQL*Plus command?（）

A. INSERT
B. UPDATE
C. SELECT
D. DESCRIBE
E. DELETE
F. RENAME

单项选择题Which object privileges can be granted on a view?（）

A. none
B. DELETE, INSERT,SELECT
C. ALTER, DELETE, INSERT, SELECT
D. DELETE, INSERT, SELECT, UPDATE