You may want to do this in three steps.
1. First create the buffer and save the buffer as a new file say, "buffer"
2. Then use the query to select records that satisfy soil type and
vegetation criteria.
save the results of the query also as a new file, say "queryResults".
now open the tables buffer and QueryResults and run the following query
select * from queryResults,buffer
where buffer.obj within queryresults.obj
now the choice of operator ( e.g., within, etc) will depend on whether you
want to select all the polygons whose centroid is within the buffer
within) or polygons are entirely within the Buffer ( entirely within) or
polygons intesrects with buffer at a least one point (intersects(.
i hope this helps.
Rajeev Saraf, Ph.D.
Co-Founder
Manchitra Services (P) Ltd.
W-25, G.K. I
New Delhi 110048
INDIA
PH: 91-11-6443201
mobile: 98100-06581
e-mail: [EMAIL PROTECTED]
www.manchitraservices.com
www.manchitra.com
----- Original Message -----
From: "PRICE, Bronwyn" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Wednesday, May 16, 2001 5:26 PM
Subject: MI-L Selecting within a buffer
> Dear Listers,
>
> I was thinking that this should be easy.
> I cant seem to access the map-Info list archives today so sorry if this is
> something that has been covered before.
>
> I have a table of data for a polygon map which includes a column of values
> representing soil type and a similar table of the same area but with
> different shaped polygons representing vegetation type.
> I also have an OS map of the area (with rivers etc as polylines). What I
> want to do is select all areas with say soil type 1, vegetation type 2 and
> within a particular distance from a river (say 1 km for convenience sake).
>
> I have no problem selecting all areas with soil type 1 and vegetation type
> 2.
> I am having problem getting the areas that are within 1 km of a river.
> I thought perhaps I could make a 1km buffer around the rivers and then do
a
> query to select the areas within the buffer with soil type 1 and
vegetation
> type 2. However, I cant seem to figure out how to do this.
> Once I create the buffer I am a bit lost. I dont really have any
experience
> with SQL.
>
> I guess my problem is something to do with the fact that the buffer table
> has only one row with no info in it and there is no link to the other
> tables. I could be making that up though.
>
> Either way I would appreciate any help anyone could offer
>
> Thanks in advance
>
> Bronwyn
>
> PS We dont have MapBasic
>
> --------------------------------------------------------------------------
--
> ------------
> Bronwyn Price
> Research Assistant in GIS
>
> GEMRU
> Cheltenham and Gloucester College of Higher Education
> Francis Close Hall
> Swindon Rd
> Cheltenham
> GL50 4AZ
>
> [EMAIL PROTECTED]
>
> Ph:++44 (0)1242 532 938
> Fax: ++44 (0)1242 543 283
> --------------------------------------------------------------------------
--
> -----------
>
>
>
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