11. 獲取所有員工當前的manager

獲取所有員工當前的manager，如果當前的manager是自己的話結果不顯示，當前表示to_date='9999-01-01'。 結果第一列給出當前員工的emp_no,第二列給出其manager對應的manager_no。 CREATE TABLE `dept_emp` ( `emp_no` int(11) NOT NULL, `dept_no` char(4) NOT NULL, `from_date` date NOT NULL, `to_date` date NOT NULL, PRIMARY KEY (`emp_no`,`dept_no`)); CREATE TABLE `dept_manager` ( `dept_no` char(4) NOT NULL, `emp_no` int(11) NOT NULL, `from_date` date NOT NULL, `to_date` date NOT NULL, PRIMARY KEY (`emp_no`,`dept_no`));

輸入描述:

無

輸出描述:

select d1.emp_no, d2.emp_no as manager_no
from dept_emp as d1, dept_manager as d2
where d1.dept_no = d2.dept_no
    and d1.emp_no <> d2.emp_no
    and d1.to_date = '9999-01-01'
    and d2.to_date = '9999-01-01'

12. 獲取所有部門中當前員工薪水最高的相關資訊

題目描述

獲取所有部門中當前員工薪水最高的相關資訊，給出dept_no, emp_no以及其對應的salary CREATE TABLE `dept_emp` ( `emp_no` int(11) NOT NULL, `dept_no` char(4) NOT NULL, `from_date` date NOT NULL, `to_date` date NOT NULL, PRIMARY KEY (`emp_no`,`dept_no`)); CREATE TABLE `salaries` ( `emp_no` int(11) NOT NULL, `salary` int(11) NOT NULL, `from_date` date NOT NULL, `to_date` date NOT NULL, PRIMARY KEY (`emp_no`,`from_date`));

輸入描述:

無

輸出描述:

select d.dept_no, d.emp_no, max(s.salary) as salary
from dept_emp as d, salaries as s
where d.emp_no = s.emp_no
    and d.to_date = '9999-01-01'
    and s.to_date = '9999-01-01'
group by d.dept_no

13. 從titles表獲取按照title進行分組

題目描述

從titles表獲取按照title進行分組，每組個數大於等於2，給出title以及對應的數目t。 CREATE TABLE IF NOT EXISTS "titles" ( `emp_no` int(11) NOT NULL, `title` varchar(50) NOT NULL, `from_date` date NOT NULL, `to_date` date DEFAULT NULL);

輸入描述:

無

輸出描述:

select title, count(title) as t
from titles
group by title
having t >= 2

14. 從titles表獲取按照title進行分組，注意對於重複的emp_no進行忽略

題目描述

從titles表獲取按照title進行分組，每組個數大於等於2，給出title以及對應的數目t。 注意對於重複的emp_no進行忽略。 CREATE TABLE IF NOT EXISTS "titles" ( `emp_no` int(11) NOT NULL, `title` varchar(50) NOT NULL, `from_date` date NOT NULL, `to_date` date DEFAULT NULL);

輸入描述:

無

輸出描述:

select title, count(distinct emp_no) as t
from titles
group by title
having t >= 2

15. 查詢employees表

題目描述

查詢employees表所有emp_no為奇數，且last_name不為Mary的員工資訊，並按照hire_date逆序排列 CREATE TABLE `employees` ( `emp_no` int(11) NOT NULL, `birth_date` date NOT NULL, `first_name` varchar(14) NOT NULL, `last_name` varchar(16) NOT NULL, `gender` char(1) NOT NULL, `hire_date` date NOT NULL, PRIMARY KEY (`emp_no`));

輸入描述:

無

輸出描述:

select emp_no, birth_date, first_name, last_name, gender, hire_date
from employees
where emp_no % 2 = 1
    and last_name <> 'Mary'
order by hire_date desc

16. 統計出當前各個title型別對應的員工當前薪水對應的平均工資

題目描述

統計出當前各個title型別對應的員工當前薪水對應的平均工資。結果給出title以及平均工資avg。 CREATE TABLE `salaries` ( `emp_no` int(11) NOT NULL, `salary` int(11) NOT NULL, `from_date` date NOT NULL, `to_date` date NOT NULL, PRIMARY KEY (`emp_no`,`from_date`)); CREATE TABLE IF NOT EXISTS "titles" ( `emp_no` int(11) NOT NULL, `title` varchar(50) NOT NULL, `from_date` date NOT NULL, `to_date` date DEFAULT NULL);

輸入描述:

無

輸出描述:

select t.title, avg(s.salary) as avg
from titles as t, salaries as s
where t.emp_no = s.emp_no
    and t.to_date = '9999-01-01'
    and s.to_date = '9999-01-01'
group by t.title

17. 獲取當前薪水第二多的員工的emp_no以及其對應的薪水salary

題目描述

獲取當前（to_date='9999-01-01'）薪水第二多的員工的emp_no以及其對應的薪水salary CREATE TABLE `salaries` ( `emp_no` int(11) NOT NULL, `salary` int(11) NOT NULL, `from_date` date NOT NULL, `to_date` date NOT NULL, PRIMARY KEY (`emp_no`,`from_date`));

輸入描述:

無

輸出描述:

select emp_no, salary
from salaries
order by salary desc limit 1,1

18. 查詢當前薪水排名第二多的員工編號emp_no以及其對應的薪水salary，不準使用order_by

題目描述

查詢當前薪水(to_date='9999-01-01')排名第二多的員工編號emp_no、薪水salary、last_name以及first_name，不準使用order by CREATE TABLE `employees` ( `emp_no` int(11) NOT NULL, `birth_date` date NOT NULL, `first_name` varchar(14) NOT NULL, `last_name` varchar(16) NOT NULL, `gender` char(1) NOT NULL, `hire_date` date NOT NULL, PRIMARY KEY (`emp_no`)); CREATE TABLE `salaries` ( `emp_no` int(11) NOT NULL, `salary` int(11) NOT NULL, `from_date` date NOT NULL, `to_date` date NOT NULL, PRIMARY KEY (`emp_no`,`from_date`));

輸入描述:

無

輸出描述:

select e.emp_no, s.salary, e.last_name, e.first_name
from employees as e, salaries as s
where e.emp_no = s.emp_no
    and s.to_date = '9999-01-01'
    and s.salary = (select max(salary) 
              from salaries
              where to_date = "9999-01-01"
                  and salary != (select max(salary) 
                             from salaries
                             where to_date = "9999-01-01"))

19. 查詢所有員工的last_name和first_name以及對應的dept_name

題目描述

查詢所有員工的last_name和first_name以及對應的dept_name，也包括暫時沒有分配部門的員工 CREATE TABLE `departments` ( `dept_no` char(4) NOT NULL, `dept_name` varchar(40) NOT NULL, PRIMARY KEY (`dept_no`)); CREATE TABLE `dept_emp` ( `emp_no` int(11) NOT NULL, `dept_no` char(4) NOT NULL, `from_date` date NOT NULL, `to_date` date NOT NULL, PRIMARY KEY (`emp_no`,`dept_no`)); CREATE TABLE `employees` ( `emp_no` int(11) NOT NULL, `birth_date` date NOT NULL, `first_name` varchar(14) NOT NULL, `last_name` varchar(16) NOT NULL, `gender` char(1) NOT NULL, `hire_date` date NOT NULL, PRIMARY KEY (`emp_no`));

輸入描述:

無

輸出描述:

select e.last_name, e.first_name, d2.dept_name
from employees as e left join dept_emp as d1
    on e.emp_no = d1.emp_no left join departments as d2
        on d1.dept_no = d2.dept_no

20. 查詢員工編號emp_no為10001其自入職以來的薪水salary漲幅值growth

題目描述

查詢員工編號emp_no為10001其自入職以來的薪水salary漲幅值growth CREATE TABLE `salaries` ( `emp_no` int(11) NOT NULL, `salary` int(11) NOT NULL, `from_date` date NOT NULL, `to_date` date NOT NULL, PRIMARY KEY (`emp_no`,`from_date`));

輸入描述:

無

輸出描述:

select ( 
(select salary from salaries where emp_no = 10001 order by to_date desc limit 1) -
(select salary from salaries where emp_no = 10001 order by to_date asc limit 1)
) as growth