[postgis-users] Questions about using SRID not -1

[Oscar Zamudio]

I already tried this way:

UPDATE mypoints SET the_geom = ST_SetSRID(the_geom,4326);

But I got:

ERROR:  Operation on two GEOMETRIES with different SRIDs

And I already left clear that there's no such different SRIDs as the values
are well in the range of 4326 spatial reference. Maybe.... and I am thinking
out loud, the extreme values I am using are the problems. I will check later
if a latitude strictly equal to -90 is a problem and a proper value must be
-89.9999 for example....


On Thu, Jan 21, 2010 at 4:39 PM, Kevin Neufeld <kneufeld at refractions.net>wrote:

> Hi Oscar,
>
> Yes, this is definitely possible.  Using your example...
>
> CREATE TABLE mydistance (the_geom geometry, the_name text);
> \d mydistance
>    Table "public.mydistance"
>  Column  |   Type   | Modifiers
> ----------+----------+-----------
>  the_geom | geometry |
>  the_name | text     |
>
>
> -- Insert without using an explicit SRID
>
> INSERT INTO mydistance (the_geom, the_name)
>   VALUES (ST_GeomFromText('POINT(-58.0 0.0)'),'Punto 1-1');
>
> SELECT ST_SRID(the_geom), ST_AsText(the_geom) FROM mydistance ;
>  st_srid |  st_astext
> ---------+--------------
>      -1 | POINT(-58 0)
> (1 row)
>
>
> -- specify the srid of all the geometries
> UPDATE mydistance SET the_geom = ST_SetSRID(the_geom, 4326);
>
> SELECT ST_SRID(the_geom), ST_AsText(the_geom) FROM mydistance ;
>  st_srid |  st_astext
> ---------+--------------
>    4326 | POINT(-58 0)
> (1 row)
>
>
> -- update geometry_columns (inserts appropriate row and adds appropriate
> constraints to your spatial table)
> SELECT populate_geometry_columns('mydistance'::regclass);
> \d mydistance
>    Table "public.mydistance"
>  Column  |   Type   | Modifiers
> ----------+----------+-----------
>  the_geom | geometry |
>  the_name | text     |
> Check constraints:
>    "enforce_dims_the_geom" CHECK (ndims(the_geom) = 2)
>    "enforce_geotype_the_geom" CHECK (geometrytype(the_geom) = 'POINT'::text
> OR the_geom IS NULL)
>    "enforce_srid_the_geom" CHECK (srid(the_geom) = 4326)
>
> SELECT * FROM geometry_columns WHERE f_table_name = 'mydistance';
>  f_table_catalog | f_table_schema | f_table_name | f_geometry_column |
> coord_dimension | srid | type
>
> -----------------+----------------+--------------+-------------------+-----------------+------+-------
>                 | public         | mydistance   | the_geom          |
>         2 | 4326 | POINT
> (1 row)
>
>
> Does this help?
> Cheers,
> Kevin
>
>
> On 1/21/2010 11:08 AM, Oscar Zamudio wrote:
>
>> I already stated that this is only an experiment trying to solve the
>> problem because my customer already loaded a
>> lot of data WITHOUT expliciting SRID reference..... I mean,
>>
>> INSERT INTO mydistance (the_geom, the_name) VALUES
>> (ST_GeomFromText('POINT(-58.0 0.0)',4326),'Punto 1-1');
>>
>> Is a step without SRID value that was taken years ago on their database.
>> I'm trying to avoid the reloading process
>> and taking in account that there are some functions that probably can make
>> the task,,, I began to explore them
>> without success up to now.
>>
>> Regards,
>>
>>  _______________________________________________
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>
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