Hi there
I have 2000 polygons in table A and I want to show only the polygons that
intersect with the bounding box specified in table B . So I do this:
SELECT the_geom
FROM A
WHERE st_intersects(the_geom, (select the_geom from B))
AND ST_GeometryType(the_geom) = 'ST_Polygon'
This query returns all the intersecting polygons. When I run
st_geometrytype they are all St_Polygon.
Some of the polygons are large and exceed the boxes boundary so I use this
query to trim them:
SELECT st_intersection(the_geom, (select the_geom from B)) as the_geom
FROM A
WHERE st_intersects(the_geom, (select the_geom from B))
AND ST_GeometryType(the_geom) = 'ST_Polygon'
The problem I'm having is that when I use the st_intersection, instead of
returning just St_Polygon's, it's returning other types as well:
ST_LineString
ST_MultiLineString
ST_MultiPolygon
ST_Polygon
I need to output the results to a SHP file and this is preventing me from
doing so seeing there is more than one Geom Type.
Any ideas how I can keep the results of the st_intersection as just
St_Polygons? Am I doing something wrong?
Regards
Rebecca
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