[postgis-users] Newbie question - Transfer attributes from onefeature to another

[Intengu Technologies]

Regina,

Solution 3 is would work fine, but was hoping for a solution to transfer the
attributes into one field without duplicating the poly.

Thanks for the pointer.


2008/10/6 Obe, Regina <robe.dnd at cityofboston.gov>

>  Sindile,
>
> If a polygon has one or more point features and you want to transfer the
> attributes from the point feature to the polygon feature, then what do you
> do in cases where there are multiple points in a polygon
>
> would you
>
> 1) pick the first one you hit
> 2) Sum up, take the max etc. of each
> 3) Duplicate the poly for each point?
>
> In all cases, you will want to do an intersect check
>
> (solution 1)
>  SELECT DISTINCT ON(poly.gid) poly.gid, poly.the_geom, point.somefield1 As
> somefield1, point.somefield2 As somefield2
> FROM
> table1 As poly INNER JOIN table2 As point
> ON ST_Intersects(poly.the_geom, point.the_geom)
> ORDER BY poly.gid, point.gid;
>
> (solution to 2 would look something like this)
> SELECT poly.gid, poly.the_geom, SUM(point.somefield1) As totsomefield1,
> MAX(point.somefield2) As maxsomefield2
> FROM
> table1 As poly INNER JOIN table2 As point
> ON ST_Intersects(poly.the_geom, point.the_geom)
> GROUP BY poly.gid, poly.the_geom;
>
> (solution to 3)
>   SELECT poly.gid, poly.the_geom, point.somefield1 As somefield1,
> point.somefield2 As somefield2
> FROM
> table1 As poly INNER JOIN table2 As point
> ON ST_Intersects(poly.the_geom, point.the_geom)
>
> Hope that helps,
> Regina
>
>
>
>
>
>  ------------------------------
> *From:* postgis-users-bounces at postgis.refractions.net [mailto:
> postgis-users-bounces at postgis.refractions.net] *On Behalf Of *Intengu
> Technologies
> *Sent:* Monday, October 06, 2008 4:47 AM
> *To:* PostGIS Users Discussion
> *Subject:* [postgis-users] Newbie question - Transfer attributes from
> onefeature to another
>
>  I have a polygon (table1) and a point (table2) feature and would want to
> transfer attributes from the point feature to the polygon feature based on
> whether the point feature is completely enclosed by the polygon feature.
> The polygon feature can have one or more point features.
>
> How do i transfer the attributes.
>
>
> --
> Sindile Bidla
>
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-- 
Sindile Bidla
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