1.用%来取余数,限制emp_no除以2的余数不等于0,也就是奇数,然后限制last_name不是"Mary",然后用order by desc根据hire_date逆排序

select * from employees
where emp_no%2<>0 and last_name<>"Mary"
order by hire_date desc

2.用mod()来取余数,限制emp_no除以2的余数不等于0,也就是奇数,然后限制last_name不是"Mary",然后用order by desc根据hire_date逆排序

select * from employees
where mod(emp_no,2)<>0 and last_name<>"Mary"
order by hire_date desc