[postgis-devel] [PostGIS] #548: st_numgeometries(geom) returns NULL when geom is not multi

[PostGIS]

#548: st_numgeometries(geom) returns NULL when geom is not multi
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 Reporter:  giohappy  |       Owner:  pramsey      
     Type:  defect    |      Status:  new          
 Priority:  medium    |   Milestone:  PostGIS 1.5.2
Component:  postgis   |     Version:  1.5.X        
 Keywords:            |  
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Comment(by robe):

 Giohappy,

 I know it sounds stupid, but this is by design.  The ST_Numgeometries is
 designed to only work with multi geometries.  I think it was dictated by
 the OGC spec, though I would like it to as you say do the logic thing of
 returning 1 for single geometries.

 The workaround is to wrap your geom in ST_Multi.  That will put it into a
 multi geometry casing if it is not a multigeometry and do nothing if it
 is.

 Alternatively just use ST_Dump instead.  ST_Dump is faster anyway and will
 explode out even for very nested collections.

 http://www.postgis.org/documentation/manual-1.5/ST_Dump.html

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Ticket URL: <http://trac.osgeo.org/postgis/ticket/548#comment:1>
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