牛客網sqlプログラミング問題

1.

題目は、遅くとも入社した従業員を検索するすべての情報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);

问题解答:

select *
from employees
order by hire_date desc
limit 0,1

select * from employees
where hire_date =
(select max(hire_date) from employees)

タイトル説明

入社時間最下位3位の社員全情報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);

问题解答:

select *
from
employees
where hire_date=(select distinct hire_date 
                 from employees 
                 order by hire_date desc 
                 limit 2,1);

select * from employees e1
where 2=(select count(*) 
         from employees e2 
         where e1.hire_date < e2.hire_date);