[postgis-users] Help with Query

[Clifford Snow]

First off, I'm a new at Postgis so please let me know if the right response
to my question is RTFM.

I have the NHD streams for my state that I want to import into
OpenStreetMap. When I select just the streams that I'm interested in I find
that there are numerous short linestrings (2 nodes) that I'd like to get
rid of. These linestrings are only connected at one end.  It seems like
ST_Touches() would find them. I did a simple query of

SELECT s1.gid, s2.gid from flowlines s1, flowlines s2 WHERE
ST_Touches(s1.geom,ST_PointN(s2.geom,1) and s2.pointcount = 2;

It returns 0 rows. Changing the point on s2.geom to 0 makes no difference.

Anyone have a suggestion of how I find 2 node streams that connect to
another stream?

-- 
Clifford

OpenStreetMap: Maps with a human touch
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