Multiple choice technology databases

Examine the structure of the EMPLOYEES and DEPARTMENTS tables: Evaluate this SQL statement: SELECT employee_id, e.department_id, department_name, salary FROM employees e, departments d WHERE e.department_id = d.department_id; Which SQL statement is equivalent to the above SQL statement?

  1. SELECT employee_id, department_id, department_name, Salary FROM employees WHERE department_id IN (SELECT department_id FROM departments);

  2. SELECT employee_id, department_id, department_name, salary FROM employees NATURAL JOIN departments;

  3. SELECT employee_id, d.department_id, department_name, salary FROM employees e JOIN departments d ON e.department_id = d.department_id;

  4. SELECT employee_id, department_id, department_name, salary FROM employees JOIN departments USING (e.department_id, d.department_id);

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The original query uses Oracle's old-style comma join syntax with a WHERE clause to join tables. Option C converts this to explicit ANSI JOIN syntax with an ON clause, which produces identical results - both return employee data with matching department information.