Complex query on Shapefiles attributes

[Stephen Lime]

Hi Brian: You'll be able to do this with 3.3.008 if I understand it right. Your using 1 polygon to set the bounds for another query correct? If that's the case then your example query is missing the value(s) from all the other polygons that need to be evaluated against your base expression.

Anyway with 3.3 you can dynamically change class expressions on-the-fly. Only problem is that it's busted since I added the logical expression support. It's fixed in 3.3.008 though. So your app should be a piece of cake in a few days.

Steve

<<< <bfischer at usgs.gov>  2/18 10:28a >>>
Hello Everyone,

     I have a question regarding a query on a shapefile's attributes.
Here is what I am trying to do.  I have an image where the user can click
on a polygon and retrieve it's attributes.  This part I have working and
understand.  Now I would like to take the value three of the attributes
from the polygon that the user selected and use it in a expression.  Here
is an example of the logic:  The user selected a polygon, from this I can
get the polygon's attributes called num1, num2, and num3.  I want to use
the values of num1, num2, and num3 to put into a query or class expression
like ([num1] >= [num2] and [num1] <= [num3]). From this I would get a
number of selected polygons to return to the user in a map with all the
polygons highlighted.  I am working with only the polygon features within
one shapefile.
     Can this be done with mapserv or do I need to look at doing this in
Javascript or some other language?  I would also like to comment on the
discussion of development tools for Mapserver.  For myself an
Avenue/ArcView extension would be useful.

Any suggestions would be apprecieted,
Thanks.

Brian Fischer
bfischer at usgs.gov
USGS WRD
2280 Woodale Dr.
Mounds View, MN
(612) 783-3133