Hi
I ahve two geometries say A and B in the same column.
I want to make a line between geometry A and geometry B.
How can I write the expression so that Postgresql recognizes that A and B are
in separate rows?
I have tried the following which produces a null return.
update a --p_id.image
set one = --the_geom =
(select st_makeline(st_makepoint(st_x(st_centroid(p_id.image.the_geom)),
st_y(st_centroid(p_id.image.the_geom))),
st_centroid(p_id.image.the_geom))
from p_id.image
where (p_id.image.fluid_id = '1513'
and p_id.image.description = 'A')
and (p_id.image.fluid_id = '1513'
and p_id.image.description = 'B'))
Bob
_______________________________________________
postgis-users mailing list
[email protected]
http://postgis.refractions.net/mailman/listinfo/postgis-users
