第06章_多表查询的课后练习

1.显示所有员工的姓名，部门号和部门名称。

SELECT e.last_name,e.department_id,d.department_name
FROM employees e LEFT OUTER JOIN departments d
ON e.department_id = d.department_id;

2.查询90号部门员工的job_id和90号部门的location_id

SELECT e.job_id,d.location_id
FROM employees e JOIN departments d
ON e.department_id = d.department_id
WHERE d.department_id = 90;

DESC departments;

3.选择所有有奖金的员工的 last_name , department_name , location_id , city

SELECT e.last_name ,e.commission_pct, d.department_name , d.location_id , l.city
FROM employees e LEFT JOIN departments d
ON e.department_id = d.department_id
LEFT JOIN locations l
ON d.location_id = l.location_id
WHERE e.commission_pct IS NOT NULL; #也应该是35条记录

SELECT *
FROM employees
WHERE commission_pct IS NOT NULL; #35条记录

4.选择city在Toronto工作的员工的 last_name , job_id , department_id , department_name

SELECT e.last_name , e.job_id , e.department_id , d.department_name
FROM employees e JOIN departments d
ON e.department_id = d.department_id
JOIN locations l
ON d.location_id = l.location_id
WHERE l.city = 'Toronto';

#sql92语法：
SELECT e.last_name , e.job_id , e.department_id , d.department_name
FROM employees e,departments d ,locations l
WHERE e.department_id = d.department_id
AND d.location_id = l.location_id
AND l.city = 'Toronto';

5.查询员工所在的部门名称、部门地址、姓名、工作、工资，其中员工所在部门的部门名称为’Executive’

SELECT d.department_name,l.street_address,e.last_name,e.job_id,e.salary
FROM departments d LEFT JOIN employees e
ON e.department_id = d.department_id
LEFT JOIN locations l
ON d.location_id = l.location_id
WHERE d.department_name = 'Executive';

DESC departments;

DESC locations;

6.选择指定员工的姓名，员工号，以及他的管理者的姓名和员工号，结果类似于下面的格式

employees Emp# manager Mgr#
kochhar 101 king 100

SELECT emp.last_name "employees",emp.employee_id "Emp#",mgr.last_name "manager", mgr.employee_id "Mgr#"
FROM employees emp LEFT JOIN employees mgr
ON emp.manager_id = mgr.employee_id;

7.查询哪些部门没有员工

SELECT d.department_id
FROM departments d LEFT JOIN employees e
ON d.department_id = e.department_id
WHERE e.department_id IS NULL;

#本题也可以使用子查询：暂时不讲

8. 查询哪个城市没有部门

SELECT l.location_id,l.city
FROM locations l LEFT JOIN departments d
ON l.location_id = d.location_id
WHERE d.location_id IS NULL;

SELECT department_id
FROM departments
WHERE department_id IN (1000,1100,1200,1300,1600);

9. 查询部门名为 Sales 或 IT 的员工信息

SELECT e.employee_id,e.last_name,e.department_id
FROM employees e JOIN departments d
ON e.department_id = d.department_id
WHERE d.department_name IN ('Sales','IT');