We can get a comma delimited output from a single select statement in SQL Server by using the following SQL Script.

select  stuff(( select  ',' + CountryRegionCode
                from    Person.CountryRegion
              for
                xml path('')
              ), 1, 1, '') as CodeList

use Northwind
GO

declare @CustIDs varchar(8000)

select top 10
        @CustIDs = isnull(@CustIDs + ',', '') + CustomerID
from    Customers

select  @CustIDs

GO

Using Cursor:

declare cCustomerIDs cursor for

select [CustomerID] from [dbo].[Customers] order by [CustomerID]

declare @CustomerIDs varchar(8000)

declare @CustomerID varchar(10)

open cCustomerIDs

fetch next from cCustomerIDs into @CustomerID

while @@FETCH_STATUS = 0
    begin

        set @CustomerIDs = isnull(@CustomerIDs + ',', '') + @CustomerID

        fetch next from cCustomerIDs into @CustomerID

    end

close cCustomerIDs

deallocate cCustomerIDs

select  @CustomerIDs as CustomerIDs

GO

Ans: find out the balance amount of account no: 1

select  a.SumCr as Credit ,
        b.SumDr as Debit ,
        a.SumCr - b.SumDr as Balance
from    ( select    sum(A_Amount) as SumCr
          from      tblAccount
          where     A_ID = 1
                    and A_Type = 'Cr'
        ) a ,
        ( select    sum(A_Amount) as SumDr
          from      tblAccount
          where     A_ID = 1
                    and A_Type = 'Dr'
        ) b

Ans: find out the balance amount for all the account numbers in the table:

select  a.A_ID as ID ,
        a.SumCr as Credit ,
        b.SumDr as Debit ,
        a.SumCr - b.SumDr as Balance
from    ( select    A_ID ,
                    sum(A_Amount) as SumCr
          from      tblAccount
          where     A_Type = 'Cr'
          group by  A_ID
        ) a
        inner join ( select A_ID ,
                            sum(A_Amount) as SumDr
                     from   tblAccount
                     where  A_Type = 'Dr'
                     group by A_ID
                   ) b on a.A_ID = b.A_ID

Ans: find the 5^th maxium salary:

   1: SELECT TOP 1 * FROM tblEmployee WHERE E_Salary NOT IN 

   2:     (SELECT DISTINCT TOP 4 E_Salary FROM tblEmployee ORDER BY E_Salary DESC)

   3:     ORDER BY E_Salary DESC