Query item not sold per customer for this month compare with last month

Question

Dear all,
i want to make query that show information about item sold per customer last month which is not sell again this month.
for example last month customer A buy item 1,2 and 3. This month, customer A only buy item 2. So, the query will show information item 1 and 3 which is not sell again to customer A.
Thanks a lot

Answer 1

Here's one that will show you items bought in the last 60 days but not the last 30 days.  It's not perfect but will get you on your way, some bits will also not be relevant, like the qrygroup64 part.
select     t0.cardcode,
          t0.cardname,
          t2.slpname,
          t1.itemcode,
          t1.itemname,
          t1.onhand,
          s0.[2mthqty],
          s0.[2mthdollar],
          s1.[1mthqty],
          s1.[1mthdollar],
          s2.lastsale
from
(select     t0.cardcode,
          t1.itemcode,
          sum(t1.quantity) as [2mthqty],
          sum(t1.linetotal) as [2mthdollar]
from
oinv t0
inner join
inv1 t1
on t0.docentry = t1.docentry
where t0.docdate >= getdate()-60
and t1.quantity > 0
group by     t0.cardcode,
               t1.itemcode) s0
full outer join
(select     t0.cardcode,
          t1.itemcode,
          sum(t1.quantity) as [1mthqty],
          sum(t1.linetotal) as [1mthdollar]
from
oinv t0
inner join
inv1 t1
on t0.docentry = t1.docentry
where t0.docdate >= getdate()-30
group by     t0.cardcode,
               t1.itemcode) s1
on s0.cardcode = s1.cardcode and s0.itemcode = s1.itemcode
inner join
(select     t0.cardcode,
          t1.itemcode,
          max(t0.docdate) as lastsale
from
oinv t0
inner join
inv1 t1
on t0.docentry = t1.docentry
where t0.docdate >= getdate()-60
group by     t0.cardcode,
               t1.itemcode) s2
on s0.cardcode = s2.cardcode and s0.itemcode = s2.itemcode
inner join
ocrd t0
on s0.cardcode = t0.cardcode
inner join
oitm t1
on s0.itemcode = t1.itemcode
inner join
oslp t2
on t0.slpcode = t2.slpcode
where           (s1.[1mthqty] = 0 or s1.[1mthqty] is null)
and t0.qrygroup64 = 'N'