Hi; No you can change projection any time you want, the point on your table is; You have objects in different projections but in one table. You have to find which objects are 4326 projection, and which are not...
Another method may be; Select st_xmin(the_geom), st_ymin(the_geom) from mypoints if the coordinates differ from --> Longitude 180 W = -180 180 E = 180 Latitude 90 N = 90 90 S = -90 Namely your x not between -180 and 180 and y not between -90 and 90, the objects are in an another projection. I mean firstly try to differ different projected objects.. Regards, IBO... On Thu, Jan 21, 2010 at 2:01 AM, Oscar Zamudio <[email protected]> wrote: > Hi, > I tried: > > UPDATE mypoints SET the_geom_4326=transform(the_geom,4326) > > But again I got: > > ERROR: Input geometry has unknown (-1) SRID > > It seems that once the data is without explicit SRID, they cannot > be processed later for asigning a proper SRID. > It is strange at first sight....but I'm a newbie so I don't know much about > this. > Regards, > Oscar > > On Tue, Jan 19, 2010 at 6:27 AM, ibrahim saricicek < > [email protected]> wrote: > >> Hi, >> >> Your table include objects, more than one projection.. So if there is any >> object in different projection you can't set your table projection to >> 4326... >> >> can you try this!! >> >> Create a new geometry column "the_geom_4326" >> >> then run this >> >> UPDATE table_name SET the_geom_4326=transform(the_geom,4326), >> >> then use ST_SetSRID for the new column... >> >> REgards, >> ibo... >> >> >> On Mon, Jan 18, 2010 at 7:23 PM, Oscar Zamudio <[email protected]> wrote: >> >>> Hi everybody. >>> I had no success with any of the recipes received here. >>> Could it be that a table with data loaded without SRID explicit value has >>> no chance of being updated later to the right one? >>> Regards, >>> Oscar >>> >>> >>> On Sun, Jan 17, 2010 at 1:08 PM, Oscar Zamudio <[email protected]> wrote: >>> >>>> Ben, >>>> I tried your intruction: >>>> >>>> UPDATE mypoints SET the_geom = ST_SetSRID(the_geom,4326); >>>> >>>> But I got: >>>> >>>> ERROR: Operation on two GEOMETRIES with different SRIDs >>>> >>>> Regards, >>>> Oscar >>>> >>>> On Sat, Jan 16, 2010 at 10:48 PM, Ben Madin < >>>> [email protected]> wrote: >>>> >>>>> Oscar, >>>>> >>>>> you have a couple of options as I see it. In Postgres you could just >>>>> update the geometries first. >>>>> >>>>> > UPDATE mytable SET the_geom = ST_SetSRID(the_geom,4326); >>>>> >>>>> >>>>> And for next time, assuming your data originally had some sort of >>>>> coordinate system (and it must have if it was spatial data), you can / >>>>> should use the -s flag in shp2pgsql to provide 'SRID awareness' >>>>> >>>>> In your case, I would suggest -s 4326. >>>>> >>>>> ie (using -d to drop and replace existing table >>>>> >>>>> $ shp2pgsql -s 4326 -d myshapefile myoldtablename | psql mydatabase >>>>> >>>>> >>>>> In geometry terms, I think it is unlikely that your data was stored >>>>> (spatially) as sexagesimal degrees, although it may be displayed as such >>>>> in >>>>> your GIS. >>>>> >>>>> cheers >>>>> >>>>> Ben >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> On 17/01/2010, at 2:54 , Oscar Zamudio wrote: >>>>> >>>>> > Hi, >>>>> > I'm have problems to transform my spatial data to UTM. First, this >>>>> instruction works OK: >>>>> > >>>>> > SELECT ST_Transform(ST_GeomFromText('POINT(0.0 20)',4326),22171) from >>>>> mypoints >>>>> > >>>>> > No matter if such a sentence has no meaning on what I tryin to do. >>>>> But when I did the same with my own points: >>>>> > >>>>> > SELECT ST_Transform(mypoints.the_geom,22171) from mypoints >>>>> > >>>>> > I get the following error: >>>>> > ERROR: Input geometry has unknown (-1) SRID >>>>> > SQL state: XX000 >>>>> > >>>>> > Ok, when I insert my points in my spatial enabled database I used: >>>>> > >>>>> > INSERT INTO mydistance ( the_geom, the_name ) VALUES ( >>>>> ST_GeomFromText('POINT(-58.0 0.0)'), 'Punto 1-1'); >>>>> > >>>>> > without no spatial reference system explicit so I guess the SRID is >>>>> set to "unknown" i.e. -1. Then naively I created a new column named srid >>>>> for my table and put the right value of SRID for all my data which is 4326 >>>>> (WGS84, sexagesimal degrees lat lon) in that column but still I get the >>>>> same >>>>> error. After that I created a constraint between this new srid column and >>>>> the srid column from the spatial_ref_sys table but nothing happened, the >>>>> error is still there. >>>>> > It's important to me to solve this issue because all my spatial data >>>>> was loaded from shapefiles without SRID awareness so they don't have any >>>>> SRID column. I don't want to reload data changing this so I need a method >>>>> to >>>>> alter the tables in such a way to add this new srid column to them that is >>>>> well related to the spatial context. >>>>> > Thanks and regards, >>>>> > Oscar >>>>> > _______________________________________________ >>>>> > postgis-users mailing list >>>>> > [email protected] >>>>> > http://postgis.refractions.net/mailman/listinfo/postgis-users >>>>> >>>>> _______________________________________________ >>>>> postgis-users mailing list >>>>> [email protected] >>>>> http://postgis.refractions.net/mailman/listinfo/postgis-users >>>>> >>>> >>>> >>> >>> _______________________________________________ >>> postgis-users mailing list >>> [email protected] >>> http://postgis.refractions.net/mailman/listinfo/postgis-users >>> >>> >> >> _______________________________________________ >> postgis-users mailing list >> [email protected] >> http://postgis.refractions.net/mailman/listinfo/postgis-users >> >> > > _______________________________________________ > postgis-users mailing list > [email protected] > http://postgis.refractions.net/mailman/listinfo/postgis-users > >
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