ST.IntersectionAggregate help need

Topics: Developer Forum, User Forum
May 19, 2009 at 11:29 AM
Edited May 21, 2009 at 8:38 AM

Please help: Why this do not work (return NULL)?

SELECT

ST.IntersectionAggregate([the_geom]) FROM (
SELECT the_geom FROM T1 where oid = 1
UNION
SELECT
the_geom FROM T2 where oid =
19
) AS table
 

But this work OK (return intersection polygon):

SELECT 

ST.Intersection(
(SELECT the_geom FROM T1 where oid = 1
),
(
SELECT the_geom FROM T2 where oid = 19))

Did I made some mistakes in first query? How to use ST.IntersectionAggregate() ? I allwais get NULL!?!

May 19, 2009 at 11:37 AM

Please help: Why this do not work (return NULL)?

 

ST.IntersectionAggregate([the_geom]) FROM (
SELECT the_geom FROM T1 where oid =
1
UNION
SELECT
the_geom FROM T2 where oid
= 19
) AS tableSELECT

But this work OK (return intersection polygon):

 

 

SELECT ST.Intersection(
(SELECT the_geom FROM T1 where oid = 1),
(
SELECT the_geom FROM T2 where oid = 19
))