Is it possible to create a spatial view with paramete?

Question

Is it possible to create a view with parameter like following:
SELECT GEOM FROM INTERSTATES WHERE MDSYS.SDO_FILTER(GEOM, MDSYS.SDO_GEOMETRY(2003, 8307, NULL, MDSYS.SDO_ELEM_INFO_ARRAY(1, 1003, 3), MDSYS.SDO_ORDINATE_ARRAY(?, ?, ?, ?)), 'querytype=WINDOW') = 'TRUE'
so that I can specify ???? at run time.
If not, is there a way to create a view that perform variable window query?

Answer 1

You may want to look at application contexts, that way you may have code something like this:
create or replace context gis_ctx using gis_params ;
create or replace package gis_params
as
procedure set_bounds( minx in number, miny in number, maxx in number,maxy in number );
end;
create or replace package body gis_params
as
procedure set_bounds( minx in number, miny in number, maxx in number,maxy in number )
is
begin
dbms_session.set_context( 'gis_ctx', 'minx', minx);
dbms_session.set_context( 'gis_ctx', 'miny', miny);
dbms_session.set_context( 'gis_ctx', 'maxx', maxx);
dbms_session.set_context( 'gis_ctx', 'maxy', maxy);
end ;
end ;
To use this method you´ll have to execute
gis_params.set_bounds(-3,40,-2.9,40.1) ;
before doing the select.
SELECT GEOM
FROM INTERSTATES
WHERE MDSYS.SDO_FILTER(GEOM,
MDSYS.SDO_GEOMETRY(2003,
8307,
NULL,
MDSYS.SDO_ELEM_INFO_ARRAY(1, 1003, 3),
MDSYS.SDO_ORDINATE_ARRAY(sys_context ('gis_ctx', 'minx'),
sys_context ('gis_ctx', 'miny'),
sys_context ('gis_ctx', 'maxx'),
sys_context ('gis_ctx', 'maxy'))),
'querytype=WINDOW') = 'TRUE' ;
I f you are in a web environment, read about GLOBAL CONTEXT ACCESSED GLOBALLY .
Regards, Nico.