Hi Regina Many thanks to your prompt answer, the query works great now! In my query the coordinates were in Plate Carree metres and I think I confused myself with the transform function. Much appreciated, any news on the proposed postgis book?
Cheers Mark On Tue, Mar 10, 2009 at 12:16 PM, Obe, Regina <robe....@cityofboston.gov>wrote: > Mark, > > I'm a bit confused, for your second query, are those points suppose to > represent user input and in long lat? They don't look like long lat. If > they are meant to be long lat, then your args are just backwards. > > The basic idea I think you want to do is > > 1) Take user input which I presume is in 4326 and then transform it to > Plate Carree to match your existing data? > Note ST_GeomFromText doesn't transform anything it simply states this data > is in long lat and then transform changes the coordinates to Plate Carree > > So should be > > ST_Intersects(pas_nat_iv_pnt.the_geom > ,ST_Transform(ST_GeomFromText(userinput,4326), > 32662) ) > > Hope that helps, > Regina > > ------------------------------ > *From:* postgis-users-boun...@postgis.refractions.net [mailto: > postgis-users-boun...@postgis.refractions.net] *On Behalf Of *mark balman > *Sent:* Tuesday, March 10, 2009 7:04 AM > *To:* postgis-users@postgis.refractions.net > *Subject:* [postgis-users] Help with query > > Hi all > > I am trying to create a query that returns the features intersected by a > user defined area. I can do this with the following query which works fine > and returns what I want: > > select areaname, country > FROM pas_nat_iv_pnt > where ST_Intersects(pas_nat_iv_pnt.the_geom , > ST_GeomFromText('POLYGON((-7726647.392661 408830.119563 , > -6918290.736304 408830.119563 , -6918290.736304 828801.112346 , > -7726647.392661 828801.112346 , -7726647.392661 408830.119563 ))' , 32662) > ) > > However, what I need to do is to have a user enter latitude and longitude > values and then transform these into Plate Carree coordinates, I have tried > the following query: > > select areaname, country > FROM pas_nat_iv_pnt > where ST_Intersects(pas_nat_iv_pnt.the_geom , > transform(ST_GeomFromText('POLYGON((-7726647.392661 408830.119563 , > -6918290.736304 408830.119563 , -6918290.736304 828801.112346 , > -7726647.392661 828801.112346 , -7726647.392661 408830.119563 ))' , > 32662),4326)) > > The query runs but returns no rows.. I would be most grateful if anyone > could enlighten me on what is wrong and what I need to change. > > TIA > > Mark > > ------------------------------ > > *The substance of this message, including any attachments, may be > confidential, legally privileged and/or exempt from disclosure pursuant to > Massachusetts law. It is intended solely for the addressee. If you received > this in error, please contact the sender and delete the material from any > computer. * > > ------------------------------ > > *Help make the earth a greener place. If at all possible resist printing > this email and join us in saving paper. * > > > _______________________________________________ > postgis-users mailing list > postgis-users@postgis.refractions.net > http://postgis.refractions.net/mailman/listinfo/postgis-users > >
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