Database

select pid,cid,name from
(
select 
	m.pid
	,c.cid
	,case when c.name IS null then m.name
		else c.name 
	end name
	,row_number() over(partition by m.pid order by c.name desc) as rn 

from @tblChild c
full join @tblMaster m
on  c.pid = m.pid
)x(pid,cid,name,rn)
where rn = 1
order by  pid desc

select m.pid,c.cid,c.name
from Master m
join Child c on c.pid = m.pid
and c.cid = (select max(cid) from Child c1 where c1.pid = m.pid)

SELECT [Account List].[Twin Pack]
FROM [Account List]
WHERE something NOT EXISTS (SELECT Budget.[Twin Pack]
FROM Budget
WHERE (((Budget.Month)=DateValue([Date]))));

Mycroft Holmes wrote:

Who in his right mind allows spaces in table/field names and what idiot allows reserved words to be used as field names (Date)

SELECT a.TwinPack
FROM @tblAccountList a
except
SELECT b.TwinPack
FROM @tblBudget b
WHERE b.Mnth = CONVERT(varchar(3),DATENAME(mm,GETDATE()))

SELECT [Account List].[Twin Pack]
FROM [Account List]
WHERE NOT EXISTS (SELECT 1 from Budget
WHERE Budget.[Twin Pack] = [Account List].[Twin Pack]
and Budget.Month=DateValue([Date])

SELECT 
 @customerId as customerId,
 (SELECT TOP 1 customerName FROM Customer WHERE customerId=@customerID ORDER BY customerName) AS customerName