資料庫刷題2

1、至少連續出現三次的數字

select distinct(l1.num) as consecutivenums

from logs l1, logs l2, logs l3
where l1.id + 1= l2.id
and l2.id + 1= l3.id
and l1.num = l2.num
and l2.num = l3.num

select distinct(p1.email)

from person p1, person p2
where p1.email = p2.email
and p1.id != p2.id

select d.name as department, e1.name as employer, e1.salary as salary

from employee e1 join department d
on e1.departmentid = d.id
where e1.salary >= all(select salary
from employee e2
where e1.departmentid = e2.departmentid)

select d.name as department, e.name as employee, e.salary as salary

from employee e join department d
on e.departmentid = d.id
where (e.departmentid, e.salary) in
(select departmentid, max(salary)
from employee
group by departmentid)

編寫乙個sql查詢，找出每個部門獲得前三高工資的所有員工。

select d.name as department, e1.name as employee, e1.salary as salary

from employee e1 join department d
on e1.departmentid = d.id
where 3 >= (select count(distinct salary)
from employee e2
where e1.departmentid = e2.departmentid
and e1.salary <= e2.salary)
order by department, employee, salary desc

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