SQL Query - comparing item sales over a specfic date range with qty and dollar amount

[ACME Supplies]

I ended up calling and received some help from our software companies resident SQL expert - below is the query:

SELECT
V.ItemCode,
V.ItemSupplierPartNum,
V.Description,
coalesce((select SUM(PY.QtyShipped) from vCustomerInvoiceDetail PY
where PY.ItemID = V.ItemID
and PY.InvoiceDate between '2013-5-1' and '2013-5-31')
,0) as PYQty,
coalesce((select SUM(PY.Amount) from vCustomerInvoiceDetail PY
where PY.ItemID = V.ItemID
and PY.InvoiceDate between '2013-5-1' and '2013-5-31')
,0) as PYDollars,
SUM(V.QtyShipped) As CurUnitsSold,
SUM(V.Amount) As CurDollarsSold
FROM vCustomerInvoiceDetail V
WHERE V.InvoiceDate between '2014-5-1' and '2014-5-31'
and V.SupplierAcct ='KRUGE100'
Group By V.ItemID, V.ItemCode, V.ItemSupplierPartNum, V.Description