You can do this with the query "FIND Sequence Homol AND NOT NEXT".
Richard
Keith Bradnam wrote:
>> Any acedb query gurus out there who can help me with a problem?
>> It might be that it's beyond the capabilities of the acedb query language
> in which case Ed will set me straight.
>> How do you test for the absence of a value in a tag-value pair where you
> would normally expect a value?
>> E.g. we have sequence objects with Homol tags. Associated with the Homol
> tag should be the name of a Sequence object. Occasionally though, errors
> creep in where we lose the object and are left with just a tag.
>> I would ideally like to be able to query the database to find errant
> entries like this. I thought I might be able to get away with things like
>> Find Sequence Homol AND NEXT = ""
>> But (perhaps obviously) the 'AND NEXT' can't actually step any further to
> the right as there is nowhere to go.
>> Maybe I should be looking into the dark murky world of AQL queries?
>> I guess I want a perl style 'if (defined($tag))' to test for the presence
> (or absence) of a value for any specified tag.
>> Any ideas anyone? This would be really useful to me if it is possible.
>> Keith
>> ~ Keith Bradnam - WormBase group: http://wormbase.sanger.ac.uk/> ~
> ~ The Sanger Centre, Wellcome Trust Genome Campus
> ~ Hinxton, Cambridge, CB10 1SA, UK. Tel (01223) 497516
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Richard Durbin The Sanger Centre
email: rd at sanger.ac.uk Wellcome Trust Genome Campus
http://www.sanger.ac.uk/Users/rd/ Hinxton
phone: 01223 494978 Cambridge CB10 1SA
fax: 01223 494919 UK
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