[postgis-users] typemod on st_union() results

[Sandro Santilli]

On Sat, Oct 19, 2013 at 11:15:59PM -0700, maplabs at light42.com wrote:
> Hi All -
> 
>   I have a process where I split a large number of geometries by a second set of (smaller) geometries, then recombine them using a GROUP BY gid.  Both source set and splitter set have the same SRID, and the results, and the combined results, therefore have an SRID. 
> 
>   But in the age of typemod, geometry_columns sees a big zero SRID. ugh  Using a cast inline has been suggested, but in this case, the result of the ST_Union()  can be either Polygon or Multipolygon.   As far as I know, the typemod has to know specifically which one.. 
> 

You can specify "geometry" as the type:

 ::geometry(geometry, <actual_srid>)

--strk;