[News] possible DB query bug?
Dr. Mark Neeser
neeser at usm.uni-muenchen.de
Thu Mar 18 15:43:25 CET 2004
Hi all,
while experimenting with SourceList queries to the data-base,
Jan and I found the following potential problem:
It seems that a search for a region that lies WITHIN a source list
is not logically implemented.
This is easier to understand in an example:
Suppose that we have a source list with
sourcelist: llRA=12.54,
then, a query of the form:
sl = (SourceList.llRA > 12 )
sl = (SourceList.llRA > 12.5 )
sl = (SourceList.llRA > 12.54 )
all work, but a query of the form:
sl = (SourceList.llRA > 12.55 )
does not work.
It seems that SourceList.llRA==12.54 but not > 12.55 and, therefore,
the query fails.
Of course, the search could be made to work with a multiple "or"
statement, but even in this case it seems that you can only get
back the COMPLETE source list, and not the searched for sub-section
of the source list.
Please have a look if you can repeat this at your respective sites,
and that we are just not doing an incorrect query or source list
implementation.
Cheers,
Mark
=====================================================
Dr. Mark J. Neeser
Institute for Astronomy and Astrophysics, _/ _/ _/ _/_/ _/
Ludwig-Maximilians-Universitaet Muenchen _/ _/ _/_/ _/ _/ _/ _/
_/ _/ _/ _/ _/ _/ _/_/
Scheinerstrasse 1, _/ _/ _/_/ _/ _/
D-81679 Muenchen, Germany
Tel: +49-89-2180-5995
Fax: +49-89-2180-6003
email: neeser at usm.uni-muenchen.de
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