On 28 October 2010 10:00, trevor1940
<antonys@nsom.org.uk> wrote:
Hi
I have a PostGIS table and I wish to get the location/name of multiple
points at once the command for selecting one point is
select PolyName from MyPolygones where st_Contains(the_geom,
GeomFromText('point($LAT $LONG)4326');
where $LAT $LONG are perl varables
So how can i do this if iI have 100 points without hitting the database 100
times?
hi,
Hi,
you could create one query using MULTIPOINT, something like:
ST_MPointFromText('MULTIPOINT($LAT1 $LONG1, $LAT2 $LONG2 ... $LAT100 $LONG100 )', 4326)
now you could find all polygons:
SELECT DISTINCT PolyName
FROM MyPolygones
WHERE ST_INTERSECTS(the_geom,
ST_MPointFromText('MULTIPOINT($LAT1 $LONG1, $LAT2 $LONG2 ... $LAT100 $LONG100 )', 4326)
);
where:
ST_INTERSECTS returns true if geometries have any common point
ST_MPointFromText creates brand new and shiny new MULTIPOINT geometry containing all the points
regards
Szymon