OCP-1Z0-051-V9.02-130题

130. View the Exhibit and examine the data in the EMPLOYEES table:

You want to display all the employee names and their corresponding manager names.

Evaluate the following query:

SQL> SELECT e.employee_name "EMP NAME", m.employee_name "MGR NAME"

FROM employees e ______________ employees m

ON e.manager_id = m.employee_id;

Which JOIN option can be used in the blank in the above query to get the required output? 

A. o nly inner JOIN

B. only FULL OUTER JOIN

C. only LEFT OUTER JOIN

D. only RIGHT OUTER JOIN

Answer: C

答案解析：

参考：http://blog.csdn.net/rlhua/article/details/12877591

显示所有employee names和对应的manager names

此处e代表员工表，而m代表管理人员表，所有只有左连接才能显示 all the employee names