[postgis-users] help with the Union of 2 shp

[islanis at infomed.sld.cu]

"Rémi Cura" <remi.cura at gmail.com> escribió:

> Juste use one or 2 polygon !
> you can use limits on your first query,
> or add a where condition with gid=XX, I guess you have a gid field (primary
> key).

ok i make this, and i get all suces but i can see what happening  
because i can see the answer in my quantumgis it say "detecting..." in  
the type of the table of my result, in this case in the  
"all_lines_cuadrado_merged" table, whats happening? please and thanks

*drop table if exists cuadrado;
CREATE TABLE cuadrado
AS (select ST_GeomFromText('MULTIPOLYGON(((-77 56,-52 18,-88 -27,-10  
-13,-11 38,-77 56)))',4326)as the_geom );
UPDATE cuadrado SET the_geom=ST_SetSRID(the_geom,4326);
SELECT Populate_Geometry_Columns('public.cuadrado'::regclass);
ALTER TABLE cuadrado ADD column gid serial;
ALTER TABLE cuadrado ADD COLUMN dato character varying;
ALTER TABLE cuadrado ADD PRIMARY KEY (gid);
UPDATE cuadrado SET dato='cuadrado' WHERE gid=1;

drop table if exists cuadrados;
CREATE TABLE cuadrados
AS (select ST_GeomFromText('MULTIPOLYGON(((-49 63,-32 24,-39 -7,-66  
-19,-72 -9,-74 31,-49 63)))',4326)as the_geom );
UPDATE cuadrados SET the_geom=ST_SetSRID(the_geom,4326);
SELECT Populate_Geometry_Columns('public.cuadrados'::regclass);
ALTER TABLE cuadrados ADD column gid serial;
ALTER TABLE cuadrados ADD COLUMN dato character varying;
ALTER TABLE cuadrados ADD PRIMARY KEY (gid);
UPDATE cuadrados SET dato='cuadrados' WHERE gid=1;

DROP TABLE IF EXISTS all_lines_cuadrado_merged;
CREATE TABLE all_lines_cuadrado_merged AS
SELECT ST_LineMerge(ST_ExteriorRing((ST_Dump(z.the_geom)).geom)) AS the_geom
FROM public.cuadrado z;
UPDATE all_lines_cuadrado_merged SET the_geom=ST_SetSRID(the_geom,4326);
SELECT  
Populate_Geometry_Columns('public.all_lines_cuadrado_merged'::regclass);
ALTER TABLE all_lines_cuadrado_merged ADD column gid serial;
ALTER TABLE all_lines_cuadrado_merged ADD COLUMN dato character varying;
ALTER TABLE all_lines_cuadrado_merged ADD PRIMARY KEY (gid);


DROP TABLE IF EXISTS cuadrados_parts;
CREATE TABLE cuadrados_parts AS
SELECT ST_Split(a.the_geom,z.the_geom) AS the_geom
FROM public.cuadrados a, public.all_lines_cuadrado_merged z;
UPDATE cuadrados_parts SET the_geom=ST_SetSRID(the_geom,4326);
SELECT Populate_Geometry_Columns('public.cuadrados_parts'::regclass);
ALTER TABLE cuadrados_parts ADD column gid serial;
ALTER TABLE cuadrados_parts ADD COLUMN dato character varying;
ALTER TABLE cuadrados_parts ADD PRIMARY KEY (gid);

>
> Cheers,
> Rémi-C
>
>
> 2013/12/16 J.Alejandro Martinez Linares <islanis at infomed.sld.cu>
>
>>
>> El 16/12/13 14:38, Rémi Cura escribió:
>>
>> And of course it is *a very bad idea* to try something without knowing if
>> it works on all your data !
>>
>>  You should try the complete solution on a small sample, then optimize
>> your queries, then use it on all your data...
>>
>>  Cheers,
>>
>>  Rémi-C
>>
>> ok ok, but there are 6570 rows of multipolygons, ok what can i do?, at
>> least i need to know if the entire process is working, i mean like a
>> progress bar, is there enything like that??!!! please and thanks
>>
>



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