http://www.sqlservercentral.com/blogs/samvangassql/2011/11/10/_2300_ssrs-error-_1320_-an-item-with-the-same-key-has-already-been-added/

Printed 2014/11/28 08:54PM

#SSRS error – An item with the same key has already been added

By Sam Vanga, 2011/11/10

Here is a simple yet annoying error I ran into while creating a dataset. Below is the query that I was using and it would run just fine when executed from management studio.

SELECT
CalendarYear Yr
, CalendarMonthNum Mth
, CalendarMonthName Mth
FROM
dbo.Orders o

But SSRS doesn’t like those two columns with the same name “Mth” resulting in the error “an item with the same key has already been added”.
To resolve this simply make sure that no two columns in your dataset have the same name.

~Sam



Copyright © 2002-2014 Simple Talk Publishing. All Rights Reserved. Privacy Policy. Terms of Use. Report Abuse.