Hi Robert, At the moment, BioMart doesn't directly support more than 2 datasets joins. It will be supported in the next BioMart release.
However, it is possible to bypass this limit to some extend in the current BioMart release. For example, you define importable/exportable links among three datasets: A, B and C, and want to join them. The current release can only support join between any two datasets of the three. Now what you can do is to define pointerFilter in one dataset and it actually pointing to filter that belongs to the other dataset. Let's say there is a filter named Filter1 in dataset C, you can define a pointerFilter in dataset A that points to Filter1 in dataset C. Now when you do join between dataset A and B, you actually join 3 datasets. Please refer to BioMart document for details about how to defined pointerFilters. Of course, please feel free to contact us if you need further assistance. Best regards, Junjun ________________________________ From: [email protected] [mailto:[email protected]] On Behalf Of Robert Hamon Sent: Friday, February 27, 2009 12:48 PM To: [email protected] Subject: [mart-dev] Is linking more than 2 datasets possible? I would like to link 3 datasets using the biomart web interface, is this possible? We created the link attributes and link filters in marteditor but find no way to link more then 2 datasets together in the web interface. Robert
