View the Exhibit and examine the description of the DEPARTMENTS and EMPLOYEES
tables. To retrieve data for all the employees for their EMPLOYEE_ID, FIRST_NAME, and
DEPARTMENT NAME, the following SQL statement was written: SELECT employee_id,
first_name, department_name FROM employees NATURAL JOIN departments; The
desired output is not obtained after executing the above SQL statement. What could be the
reason for this?
A.
The NATURAL JOIN clause is missing the USING clause.
B.
The table prefix is missing for the column names in the SELECT clause.
C.
The DEPARTMENTS table is not used before the EMPLOYEES table in the FROM
clause.
D.
The EMPLOYEES and DEPARTMENTS tables have more than one column with the
same column name and data type.
No of the answers is correct. The clause NATURAL JOIN can work in case when two tables have more than one column with the same name and data type. The select in the question is correct and gives the desired output
Milan, generated condition on MANAGER_ID column by NATURAL JOIN can cut some rows from result;
(upd) correct answer is D