[postgis-users] UTM/Datum SAD 69 to UTM/Datum WGS84???

[Nicolas Ribot]

> Hi Nicolas.
>  Thank you.
>  Very good.
>  My problem now is that I am receiving the following message:
>  SELECT Transform(the_geom,32723) FROM tb_my;
>  ERROR:  Input geometry has unknown (-1) SRID
>  Observing the table geometry_columns, the field srid=-1
>  Help me.
> 
>  

(hmm, my answer will look exactly like the one I sent to Mark on June, 29th...)

So, geometries in your table tb_my have no SRID (-1).
You have to explicity set an SRID for these data:

First change the SRID in the postgis metadata
(geometry_columns table):

select updateGeometrySRID('tb_my', 'the_geom', <source_srid>);

Second, use setSRID() to change internal geometries' SRID in the
geometric table:

select setSRID(the_geom, <source_srid>) from tb_my.

Then you should be able to reproject data from tb_my to another
spatial reference system using transform(...).

Nicolas