You don't need to create additional columns to check exising ones in WHERE-clause, so your query is simlply:
SELECT * FROM public.lines WHERE ST_IsClosed(lines.linestring); 2014-09-14 23:21 GMT+03:00 Christopher Braune <[email protected]>: > Hello PostGIS-Users, > > I want to select all closed lines in my dataset. I think the function > ST_IsClosed is usefull for this task. > > I tried the following SQL-Sentence: > >> > SELECT *, (SELECT ST_IsClosed(lines.linestring) AS tof) FROM public.lines > WHERE tof='TRUE'; > << > > I get this error-message: > > >> > ERROR: column "tof" does not exist > LINE 3: ...s.linestring) AS tof) FROM public.lines WHERE tof='TRUE'... > ^ > ********** Fehler ********** > > ERROR: column "tof" does not exist > SQL Status:42703 > Zeichen:131 > << > > Can anybody help me? In general I want to know how I use the > boolean-results (like ST_IsClosed) in nested queries. > > Best regards, > Christopher > _______________________________________________ > postgis-users mailing list > [email protected] > http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users > -- Darafei "Komяpa" Praliaskouski OSM BY Team - http://openstreetmap.by/ xmpp:[email protected] mailto:[email protected]
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