[postgis-users] Transform Coordinates

[Jean David TECHER]

Quoting lisek lichu <lisek.lichu at gmail.com>:

> You can also add new column in Your table

>
> SELECT
> AddGeometryColumn('','table_name','new_column_name','new_SRID','POINT',2);
>
> after that jst do:
>
> UPDATE table_name set new_column_name = Transform(old_geom_column,new_SRID);
>
> after that query You will have 2 columnt: first with old SRID ald second
> with new SRID so You can just DROP old column.
>

-- cut --

Dropping is correct but...

I advise you to use dropgeometrycolumn instead because dropping the  
old colimn will not drop the new reference tuple in geometrycomuns

select DropGeometryColumn('table_name','old_geom_column');

is available too :)

and will drop the tuple in geomtrycolumns.

It is important for GIS tools like QGIS and MapServer that use  
geometry_columns table...These tools implements the following query

' select srid ??? from geometry_column where f_table='???''

So imagine what happen if the drop column does not exist???

--david;

> Simon
>



===================
Jean David TECHER
www.davidgis.fr
06 60 46 85 05
04 99 77 16 87
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