SSIS: Unflatten a hierarchy

Question

I have an excel file that has the following columns and data
ItemNumber
Description
Attribute1
Attribute2
Attribute3
1000
A
1
2
1
1001
B
1
0
2
1002
C
2
1
1
1003
D
0
0
1
I need to output this into two tables and in the following way
ItemId
ItemNumber
Description
1
1000
A
2
1001
B
3
1002
C
4
1003
D
ItemId
AttributeId
Value
1
1
1
1
2
2
1
3
1
2
1
1
2
3
2
3
1
2
3
2
1
3
3
1
4
3
1
Essentially two questions:
1. After I create the first table, how can I provide the Id generated there to the Attributes table
2. How do I unflatten the Attibutes to multiple rows. There can only ever be three attributes Attribute1, Attribute2 and Attribute3. These need to be associated with AttributeIds 1, 2 and 3 respectively.
Thanks in advance

Answer 1

Try this,
declare @temp table (ItemNumber int,Description varchar(10), Attribute1 int, Attribute2 int, Attribute3 int)
insert into @temp values(1000,'A',1,2,1)
insert into @temp values(1001,'B',1,0,2)
insert into @temp values(1002,'C',2,1,1)
insert into @temp values(1003,'D',0,0,1)
if OBJECT_ID('tempdb..#temp') IS NOT NULL DROP TABLE #temp
select row_number() over (order by description) ItemId, * into #temp from @temp
select ItemId, Replace(Attributes,'Attribute','') as AttributeId, Value from #temp
unpivot(Value for Attributes in (Attribute1,Attribute2,Attribute3)) upvt
where Value <> 0
select ItemId,ItemNumber, Description from #temp