[postgis-users] transform - update lake set the_geom=transform(the_geom, 26971)

[Nicolas Ribot]

> I have a table city which contains Multipolygons (SRID=4326) in latitude and
> longitude. To project it to  a plane coordinate (SRID=26971), I did:
>
>   update lake set the_geom=transform(the_geom, 26971);
>
> It ran without any error. But some of the resulted values in the_geom column
> became null or empty.
>
> Any hitnts why it did this?
>
> Before the transformation, I viewed the table with QuantumGIS, it looked OK.
> Afterwards, QuantumGIS showed nothing.
>

Hi,
Verify that your input table has longitude-latitude values as X-Y
coordinate, not the contrary.

Also, if some input data fall outside of the range of acceptable
values for the 26971 projection, these data won't be transformed =>
null values.

Nicolas