Practice.sql

--求一列中第二大的数据

select max(PersonId) from Address where PersonID not in (select MAX(PersonId) FROM Address)

--Use < is faster than not in
SELECT max(Salary)
FROM Employee
WHERE Salary <
(SELECT max(Salary)
FROM Employee);

--找出最个部门的工资收入最高的3个人

Select dep.Name as Department, emp.Name as Employee, emp.Salary from Department dep, 
Employee emp where emp.DepartmentId=dep.Id and 
(Select count(distinct Salary) From Employee where DepartmentId=dep.Id and Salary>emp.Salary)<3

--No more than 2 higher salary can be found in the departement.