Evaluate these two SQL statements: SELECT last_name, salary , hire_date FROM EMPLOYEES ORDER BY salary DESC; SELECT last_name, salary, hire_date FROM EMPLOYEES ORDER BY 2 DESC;

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  1. The two statements produce identical results.

  2. The second statement returns a syntax error.

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

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

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Correct Option: A
Explanation:

To solve this question, the user needs to understand the SQL SELECT statement and the ORDER BY clause. The ORDER BY clause is used to sort the result set in ascending or descending order based on one or more columns.

Now, let's go through each option and explain why it is right or wrong:

A. The two statements produce identical results. This option is correct. Both SQL statements select the same columns from the same table, and they both sort the results by the salary column in descending order. The syntax used to specify the column to sort by is different (column name vs. column position), but they are functionally equivalent.

B. The second statement returns a syntax error. This option is incorrect. The second SQL statement is also valid syntax and should execute without errors.

C. There is no need to specify DESC because the results are sorted in descending order by default. This option is incorrect. The ORDER BY clause sorts the result set in ascending order by default. If you want to sort in descending order, you need to explicitly specify the DESC keyword.

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. This option is incorrect. The column alias does not affect the sorting behavior of the ORDER BY clause. It only changes the name of the column in the result set.

Therefore, the correct answer is:

The Answer is: A

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