[postgis-users] [From Oracle Spatial to PostGIS] How to store rectangles?

[Simon Greener]

Mulone,

These scripts work and, perhaps, gives you an idea how to go about what you want to do.

1. Generate Test Data in Oracle
--optimized_oracle.sql
=============================================
DROP   TABLE Conversion PURGE;
CREATE TABLE Conversion ( gid integer, geom mdsys.sdo_geometry );
SET FEEDBACK OFF
    INSERT INTO COnversion
      SELECT rownum,
             mdsys.sdo_geometry(2003,4326,NULL,
                   MDSYS.SDO_ELEM_INFO_ARRAY(1,1003,3),
                   MDSYS.SDO_ORDINATE_ARRAY(
                         ROUND(lon,2),
                         ROUND(lat,2),
                         ROUND(lon+dbms_random.value(0.1,1.0),2),
                         ROUND(lat+dbms_random.value(0.1,1.0),2)
                         ))
       FROM (SELECT dbms_random.value(147,149) as lon,
                    dbms_random.value(-44,-42) as lat
               FROM DUAL)
     CONNECT BY LEVEL <= 500;
commit;
select distinct sdo_geom.validate_geometry(geom,0.005) from conversion;

-- Write CSV header and data
SET ECHO OFF
@write_csv
===========================================================

2. Dump CSV file
--write_csv.sql
===========================================================
SET NEWPAGE 0
SET SPACE 0
SET LINESIZE 9999
SET PAGESIZE 0
SET FEEDBACK OFF
SET VERIFY OFF
SET HEADING OFF
SET MARKUP HTML OFF
SET TRIMSPOOL ON
SET LONG 4000
SET LONGCHUNKSIZE 500
SET TERMOUT OFF
SET SQLPROMPT OFF
spool c:\temp\conversion.csv
select 'gid,bottomleftlon,bottomleftlat,toprightlon,toprightlat' from dual;
select gid || ',' || bottomleftlon || ',' || bottomleftlat || ',' || toprightlon || ',' ||  toprightlat
  from (select a.gid, 
               sum(case when MOD(rownum,2) = 1 then v.x else null end) as bottomleftlon, 
               sum(case when MOD(rownum,2) = 1 then v.y else null end) as bottomleftlat, 
               sum(case when MOD(rownum,2) = 0 then v.x else null end) as toprightlon, 
               sum(case when MOD(rownum,2) = 0 then v.y else null end) as toprightlat
          from conversion a, 
               table(sdo_util.getvertices(a.geom)) v
        group by a.gid
        order by 1
       );
spool off
SET SQLPROMPT 'SQL> '
===========================================================

3. Load into PostGIS
--optimized_postgis.sql
===========================================================
DROP   TABLE Conversion;
CREATE TABLE Conversion (
  GID           integer,
  bottomLeftLon double precision,
  bottomLeftLat double precision,
  topRightLon   double precision,
  topRightLat   double precision);
COPY Conversion ( gid,bottomLeftLon,bottomLeftLat,topRightLon, topRightLat )
    FROM 'c:/temp/conversion.csv'
    WITH 
          DELIMITER AS ','
          CSV HEADER ;
/*
insert into Conversion (bottomLeftLon,bottomLeftLat,topRightLon, topRightLat)
VALUES (147,-43,148,-42),
       (148,-44,149,-43);
*/

SELECT addGeometryColumn('postgis','conversion','bbox','4326','POLYGON','2'); 
UPDATE Conversion set bbox = ST_SetSRID(ST_MakeBox2D(ST_MakePoint(bottomLeftLon,bottomLeftLat), ST_MakePoint(topRightLon, topRightLat)),4326);

SELECT gid, ST_AsText(bbox)
  FROM Conversion
  LIMIT 10;

-- Create a spatial index for faster querying
CREATE INDEX conversion_bbox ON conversion USING GIST ( bbox );

-- Now, use the newly indexed spatial column in the spatial equivalent of the above query
SELECT count(*)
  FROM conversion
 WHERE bbox && SetSRID('BOX3D(148.5 -43.1, 148.9 -42.4)'::box3d,4326) ;
===========================================================

regards
Simon
-- 
SpatialDB Advice and Design, Solutions Architecture and Programming,
Oracle Database 10g Administrator Certified Associate; Oracle Database 10g SQL Certified Professional
Oracle Spatial, SQL Server, PostGIS, MySQL, ArcSDE, Manifold GIS, FME, Radius Topology and Studio Specialist.
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Website: www.spatialdbadvisor.com
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Latitude: -43.01530 (43° 00' 55" S)
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