关于HQL的连接查询，说法错误的是（）。A、inner join 或 join用于内连接B、inner join fetch或 join fetch用于迫切内连接C、left outer join fetch 或 left join fetch用于迫切左外连接D、right outer join fetch 或 right join fetch用于迫切右外连接

ExhibitExamine the data in the EMPLOYEES and DEPARTMENTS tables.You want to retrieve all employees‘ last names, along with their manager‘s last names and their department names. Which query would you use?（）

A. SELECT last_name, manager_id, department_name FROM employees e FULL OUTER JOIN department d ON (e.department_id = d.department_id);

B. SELECT e.last_name, m.last_name, department_name FROM employees e LEFT OUTER JOIN employees m on ( e.managaer_id = m.employee_id) LEFT OUTER JOIN department d ON (e.department_id = d.department_id);

C. SELECT e.last_name, m.last_name, department_name FROM employees e RIGT OUTER JOIN employees m on ( e.manager_id = m.employee_id) FULL OUTER JOIN department d ON (e.department_id = d.department_id);

D. SELECT e.last_name, m.last_name, department_name FROM employees e LEFT OUTER JOIN employees m on ( e.manager_id = m.employee_id) RIGT OUTER JOIN department d ON (e.department_id = d.department_id);

E. SELECT e.last_name, m.last_name, department_name FROM employees e RIGHT OUTER JOIN employees m on ( e.manager_id = m.employee_id) RIGHT OUTER JOIN departments d ON (e.department_id = d.department_id)

F. SELECT last_name, manager_id, department_name FROM employees e JOIN department d ON (e.department_id = d.department_id);

Talk about the difference between INNER JOIN and LFET JOIN.

以下哪项用于左连接( )

A.JOIN

B.RIGHT JOIN

C.LEFT JOIN

D.INNER JOIN

join的外连接方式有（ ）。

A.右连接

B.自然连接

C.全连接

D.左连接

Click the Exhibit button and examine the data in the EMPLOYEES and DEPARTMENTS tables.You want to retrieve all employees‘ last names, along with their managers‘ last names and their department names. Which query would you use?（）

A.SELECT last_name, manager_id, department_name FROM employees e FULL OUTER JOIN departments d ON (e.department_id = d.department_id);

B.SELECT e.last_name, m.last_name, department_name FROM employees e LEFT OUTER JOIN employees m on ( e.manager_id = m.employee_id) LEFT OUTER JOIN departments d ON (e.department_id = d.department_id);

C.SELECT e.last_name, m.last_name, department_name FROM employees e RIGHT OUTER JOIN employees m on ( e.manager_id = m.employee_id) LEFT OUTER JOIN departments d ON (e.department_id = d.department_id);

D.SELECT e.last_name, m.last_name, department_name FROM employees e LEFT OUTER JOIN employees m on ( e.manager_id = m.employee_id) RIGHT OUTER JOIN departments d ON (e.department_id = d.department_id);

E.SELECT e.last_name, m.last_name, department_name FROM employees e RIGHT OUTER JOIN employees m on ( e.manager_id = m.employee_id) RIGHT OUTER JOIN departments d ON (e.department_id = d.department_id);

F.SELECT last_name, manager_id, department_name FROM employees e JOIN departments d ON (e.department_id = d.department_id) ;

A．错误

B．正确

用SQL语句进行表的查询操作，使用 ()语句。如果要进行分组查询，应使用 ()子句;如果要对查询结果进行排序，要使用 () 子句;查询使用连接操作时，可以使用的外连接方式主要有左连接() ，右连接() ，全连接 () 等几种。

A UPDATE ， ORDER BY， GROUP BY， LEFT JOIN， RIGHT JOIN， FULL JOIN

B SELECT ， GROUP BY， ORDER BY， LEFT JOIN，RIGHT JOIN， FULL JOIN

C SELECT ， ORDER BY ， GROUP BY ， LEFT JOIN， RIGHT JOIN，FULL JOIN

D SELECT ，GROUP BY ， ORDER BY ， RIGHT JOIN， LEFT JOIN， FULL JOIN