Question 16

Explanation

Correct answer: The two statements produce identical results.

Analyze the two SQL queries carefully:

Exhibit 1:

SELECT last_name, salary, hire_date
FROM employees
ORDER BY salary DESC;

• Orders the result by the salary column in descending order.

Exhibit 2:

SELECT last_name, salary, hire_date
FROM employees
ORDER BY 2 DESC;

• Orders the result by the second column in the SELECT list, which is salary.

• ORDER BY 2 means order by the second selected column.

• Adding DESC makes it descending order.

Now, let's examine the statements:

1. The two statements produce identical results.
   True

• Both sort by the salary column descending.

• ORDER BY salary DESC and ORDER BY 2 DESC are equivalent here.

1. The second statement returns a syntax error.
   False

• Ordering by column position is valid in SQL.

1. There is no need to specify DESC because the results are sorted in descending order by default.
   False

• Default order is ascending, so DESC is necessary to sort descending.

1. The two statements can be made to produce identical results by adding a column alias for the salary column in the second SQL statement.
   False

• Adding an alias is unnecessary since ordering by column position already works.