Create database Test6

create table Employee 
(
Id int primary key identity(1,1)  not null,
Salary int not null,
)
Insert into Employee(Salary) select 100
union all select 200
union all select 300

select top 2 Salary from Employee  
select max(Salary) as SecondHighestSalary  from Employee where Salary<(select max(Salary) from Employee)