SQL Group By Certain Amounts - sql

Question

I have an order table which has the customer id and order amount. I want to join these orders but joined orders cannot exceed a certain amount. An example below:
Let's say the maximum amount is 33 pallets and I have a table like this:
Order ID Client ID Amount
1 100001 10
2 100001 22
3 100001 13
4 100001 33
5 100001 1
6 100001 5
7 100001 6
The result should be:
Order ID Client ID Amount Joined ID Joined Amount
1 100001 10 100001A 32
2 100001 22 100001A 32
3 100001 13 100001B 13
4 100001 33 100001C 33
5 100001 1 100001D 12
6 100001 5 100001D 12
7 100001 6 100001D 12
Here, if we can also come up with a way to ad orders numbered 5,6,7 to joined order 10001B it would be great. But even this solution will be enough.
I have a few ideas on how to solve this but I couldn't really come up with a working solution. I'll be handling around 2000 Order Ids like this, so also I don't want this to be a slow operation. I'm using SQL Server 2014

Answer 1

you can find proposed solution (sql definition) with help of recursive CTE here: http://sqlfiddle.com/#!6/285c16/45
basicaly CTE iterates ordered list (by clientID, orderID) and evaluate if summed amount is not over 33.
i have added next clientID to mock data, to test correct subcount criteria evaluation.
here is query to obtain results:
-- prepare numbering for iteration
with orders_nr
as
(
select row_number() over(order by clientID, id) as [nr],
o.*
from orders o
)
,
-- prepare sum totals
re
as
(
select id, amount, amount as amount_total ,o.[nr] as nr,
clientID
from orders_nr o
where o.[nr]=1
UNION ALL
select o.id, o.amount,
CASE WHEN o.clientID <> r.clientID then o.amount
ELSE o.amount+ r.amount_total END,
o.[nr] as nr, o.clientID
from orders_nr o join re r
on (o.[nr]=r.[nr]+1)
)
,
-- iterate total - evaluate current criteria (<=33)
re2 as
(
select re.id, re.amount, re.amount_total,
re.[nr] as [group], re.[nr], re.clientID
from re
where re.[nr]=1
UNION ALL
select r.id, r.amount,
CASE WHEN r.amount+re2.amount_total >33
OR r.clientID<>re2.clientID
then r.amount ELSE re2.amount_total+r.amount END
as amount_total,
CASE WHEN r.amount+re2.amount_total >33
OR r.clientID<>re2.clientID THEN
r.[nr] ELSE re2.[group] END as [group], r.[nr], r.clientID
from re r join re2
on (r.[nr]=re2.[nr]+1 )
)
, group_total
AS
(
select [group], clientID, max(amount_total) as total
FROM re2
group by [group], clientID
),
result
as
(
select
r.id, r.clientID, r.amount,
cast(r.clientid as varchar(20))
+'-'+char(64+cast(
dense_rank()
over( partition by r.clientID
order by r.[clientID], r.[group])
as varchar(3))) as joinedID
, gt.total as joinedAmount
from re2 as r join group_total gt
on (r.clientID=gt.clientID AND r.[group]=gt.[group])
)
select * from result

Answer 2

Not certain if I'm understanding the question correctly, but you might try
select [Client ID], [Joined ID], sum([Amount]) as Total_Amount
from [table_name]
group by [Client ID], [Joined ID]
having sum([Amount]) <= 33
It leaves off the Order ID, but since it looks to be unique, you can't use it in a group by.
Edit was to add the having clause in the query to say we can't have something that adds up to more than 33.

Answer 3

I tried to solve with simple selects and without using an explicit cursor but it was a little hard in that way.
I've solved it and got exactly what you wanted with:
a TempTable, a cursor, a counter for checking the sum of sequent amounts, CHAR() function to generate letters; I calculated the values and inserted into temp table finally updated the temp table, following is what I tried and the DEMO IS HERE.
create table #tbl_name
(OrderID int,
ClientID int,
Amount int,
joinedId varchar(15) ,
joinedAmount int)
insert #tbl_name(OrderID,ClientID,Amount)
select OrderID,ClientID,Amount from tbl_name
declare cr cursor for
select orderId,
clientId,
amount
from tbl_name
order by OrderId
declare #summedAmount int,
#orderId int,
#clientId int,
#amount int,
#counter int
set #summedAmount=0
set #counter=65
open cr
fetch from cr into #orderId,#clientId,#amount
while (##fetch_status=0)
begin
if (#amount + #summedAmount < 33)
begin
set #summedAmount=#summedAmount+#amount
update #tbl_name
set joinedId=cast(#ClientId as varchar(10))+char(#counter),
joinedAmount=#summedAmount
where orderId=#orderId
end
else if (#amount + #summedAmount >33)
begin
set #counter=#counter+1
set #summedAmount=#amount
update #tbl_name
set joinedId=cast(#ClientId as varchar(10))+char(#counter),
joinedAmount=#Amount
where orderId=#orderId
end
fetch from cr into #orderId,#clientId,#amount
end
close cr
deallocate cr
go
with CTE as
(
select JoinedId, max(joinedAmount) mx
from #tbl_name
group by JoinedId
)
update #tbl_name
set joinedAmount = CTE.mx
from #tbl_name
join CTE on #tbl_name.JoinedId=CTE.JoinedId
select * from #tbl_name
drop table #tbl_name