Hi Paul, this is a little bit complicated. I try explain it below: You can combine individual filters using 'AND'. However in addition to simple filters there are also complex filters such as 'IN list' filters. They act as an equivalent to a multiple 'OR' statement. In addition there are filters that allow for simple negation (boolean filters). At the end it all boils down to SQL logical operation so you can see statements such as (sth = A OR sth =B) AND sth !=C and sth=D etc
Please let me know if this is still unclear a On Thu, Jan 5, 2012 at 5:20 AM, Paul Kersey <[email protected]> wrote: > Hello > > does Mart provide any support for logical operations other than AND? > > there's a paper by Peter Karp (describing his own query system) where he > asserts: > > "BioMart includes a form of ‘not’ but on an individual filter element only" > > which I presume means that you can't say "A, not B" but you can say "A and > 'NOT B'" > > is this correct? is there any documentation for how you can do this? > > best wishes, > > Paul > > -- > http://www.ensemblgenomes.org > Extending Ensembl across the taxonomic space. > > ------------------------------**------------------------------**------ > Dr. Paul Kersey > Team Leader, PANDA Dataflow > EMBL-European Bioinformatics Institute Tel: +44-(0)1223-494601 > Wellcome Trust Genome Campus, Hinxton Fax: +44-(0)1223-494468 > Cambridge CB10 1SD, UK email: [email protected] > > ______________________________**_________________ > Users mailing list > [email protected] > https://lists.biomart.org/**mailman/listinfo/users<https://lists.biomart.org/mailman/listinfo/users> >
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