题目地址
https://www.nowcoder.com/activity/oj
6.查找所有员工入职时候的薪水情况，给出emp_no以及salary， 并按照emp_no进行逆序
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));
这题存在坑点，一个人的工资记录可能不止一个，存在涨工资的可能
这里利用from_date和hire_date来确定入职时的工资
select t1.emp_no,salary
from employees t1
inner join salaries t2
on t1.emp_no=t2.emp_no and t1.hire_date=t2.from_date
order by t1.emp_no desc;
7.题目描述
查找薪水涨幅超过15次的员工号emp_no以及其对应的涨幅次数t
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));
【SQL语句训练6-10】按工号聚合后计算工资记录数，大于15的算一条
select emp_no, count(salary) as t
from salaries
group by emp_no
having t > 15;
8.题目描述
找出所有员工当前(to_date='9999-01-01')具体的薪水salary情况，对于相同的薪水只显示一次,并按照逆序显示
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));
select distinct salary
from salaries
where to_date = '9999-01-01'
order by salary desc;
9.题目描述
获取所有部门当前manager的当前薪水情况，给出dept_no, emp_no以及salary，当前表示to_date='9999-01-01'
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));
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));
select t1.dept_no, t1.emp_no, t2.salary
from dept_manager as t1
inner join salaries as t2
on t1.emp_no = t2.emp_no
and t1.to_date = '9999-01-01'
and t2.to_date = '9999-01-01';
10.获取所有非manager的员工emp_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));
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));
select emp_no
from employees
where emp_no not in
(select emp_no from dept_manager);
