[postgis-users] Migration from SQLServer to PostGIS

Vinko Vrsalovic vinko at cprsig.cl
Wed Feb 5 15:35:51 PST 2003


Hello,

	I'm trying to migrate a M$SQL database with 'spatial'
	information to PostGIS:

	It has 3 fields that determine the spatial location of the data.

		- Coordinate system: 	These are the possible values:
					=> Lat/Lon
					=> UTM 18S PSAD 56
					=> UTM 18S SAD 69
					=> UTM 18S WGS 84
					=> UTM 19S PSAD 56
					=> UTM 19S SAD 69
					=> UTM 19S WGS 84
		- Geometry Type: 
					=> Point
					=> Line
					=> Polygon

		- Coordinates:		The actual values according to
		  			the coordinate system.

	At first, I thought to do a big import from to Postgres, doing a
	generic geometry column (GEOMETRY type) with the appropriate
	SRID's, but, according to the docs, I cannot create a single
	column with multiple SRID's, which makes a lot of sense, BTW.

	The objective is also to unify the coords system, leaving all
	data in one system, probably UTM19S WGS84. My idea was to use 
	PostGIS transform() function, instead of transforming on my own 
	in the import app; the options I'm evaluating right now are:

	- Do multiple geom columns on the table, one for each SRID, and
	  then write a stored procedure (or a script, or whatever) 
	  to build the final table

	- Do the transform in the import app itself, using MapScript,
	  which I don't want to do :-)

	Any other ideas?

	And, finally, another question, what's the SRID for latlon
	coords?

	I've done: 
	select * from spatial_ref_sys where proj4text like '%latlon%';

	But no results are given.

	What can I do to transform latlon into whichever UTM we finally
	choose?

Thanks a lot,
-- 
Vinko Vrsalovic <el[|- at -|]vinko.cl>
http://www.cprsig.cl



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