Pivot Task Error - Duplicate pivot key

I am using the pivot task to to a pivot of YTD-Values and after that I use derived columns to calculate month values and do a unpivot then.

All worked fine, but now I get this error message:

[ytd_pivot [123]] Error: Duplicate pivot key value "6".

The settings in the advanced editor seem to be correct (no duplicate pivot key value) and I am extracting the data from the source sorted by month.

Could it be a problem that I use all pivot columns (month 1 to 12) in the derived colum transformation and they aren′t available at this moment while data extracting is still going on?

any hints?

Cheers
Markus

The pivot transform takes values like:

cust# Product Qty

-- -

1 Ham 4

1 Chips 2

1 Flan 1

2 Chips 3

2 Beer 19

and produces rows like:

cust# HamQty ChipsQty FlanQty BeerQty

-- - - - -

1 4 2 1 null

2 null 3 null 19

so what to do with input data like this?

cust# Product Qty

-- -

1 Ham 4

1 Chips 2

1 Chips 5

Which value should go into the ChipsQty column 2 or 5?

Most application would want 7, and so we suggest that the pivot be preceded by an aggregate transform to ensure that there is only 1 row for each distinct value of the pivot key. If not, you will see the error you report.

hope this helps