How do I prevent double counting in many-to-many relation

[system]

Hi all,

I have a situation in a universe, when there is a many-to-many relationship between two tables, program title and category- a program title can belong to more than one category like Movies and Action, so in grand total of all titles within all category, the total gets inflated or doubled as titles can be counted twice or three times,depending on how many categories one program title belongs to.

In an OLTP universe, how do I prevent this ??

The three tables are:
Prog_CATegory >>>>Cat_Link>>>>Program_Title

PLEASE HELP!!

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anushajq (BOB member since 2005-02-22)

[system]

It sounds like you have a fan trap. You can check the Designer FAQs for info on how to deal with a fan trap.

Here’s one post to get you started:

FAQ: Designer

What is a fan trap, why is it a problem, and how do I resolve it? Dave Rathbun describes it well in his presentation, ZEN and the ART of Universe Design. Which is located here: http://www.dagira.com/conference-presentations/ Here is a quick synopsis of Fan Trap from his presentation: A Fan Trap is a one - many - many relationship. This would happen if you are using a Summary and a Detail table in one query. Fan Traps can cause numbers to multiply. Business Objects resolves this t…

You can also check the Designer manuals for info on fan traps.

Good luck,
Judy

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JMulders (BOB member since 2002-06-20)