> I used the following query to make a buffer of 1m iutward to a convexull
> created by union of a set of polygons. But it gives an error.Why?
> SELECT ST_As_Text(ST_Buffer (foo.the_geom, 1)) from (select
> (ST_ConvexHull(ST_Union(the_geom))) from building_poly) As foo;
Hi Sanjjewa,
The function is st_astext, not st_as_text.
Furthermore, you are calling foo.the_geom in the outer query though
the column in the inner query is not called 'the_geom'.
Is this works better with an alias on the convexHull operation ?:
SELECT ST_AsText(ST_Buffer (foo.the_geom, 1))
from (
select ST_ConvexHull(ST_Union(the_geom)) as the_geom
from building_poly
) As foo;
Nicolas
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