This page describes the join of ccm21.catchments with the clc

-- Un essai sur la Bretagne pour voir
DROP TABLE IF EXISTS clc.clipped_bretagne;
CREATE TABLE clc.clipped_bretagne AS
SELECT intersected.clcgid, intersected.gid, clipped_geom
FROM (SELECT clc.gid as clcgid, c.gid, ST_Multi(ST_Intersection(clc.the_geom, c.the_geom)) AS clipped_geom
        FROM  clc.clc00_v2_europe clc INNER JOIN ccm21.catchments c
        ON  ST_Intersects (c.the_geom,clc.the_geom)
        WHERE c.wso_id IN (SELECT wso_id FROM france.wso WHERE area='Bretagne')
        AND substring(code_00 from 1 for 1)='1')  AS intersected;--3721 lines   
ALTER TABLE clc.clipped_bretagne add column id serial PRIMARY KEY;
-- ajout dans la table geometry_columns pour référencement rapide sous Qgis
INSERT INTO geometry_columns(f_table_catalog, f_table_schema, f_table_name, f_geometry_column, coord_dimension, srid, "type")
SELECT '', 'clc', 'clipped_bretagne', 'the_geom', ST_CoordDim(clipped_geom), ST_SRID(clipped_geom), MULTIPOLYGON
FROM clc.clipped_bretagne  LIMIT 1;

-- il ne s'affiche pas... essai réduit OK
DROP TABLE IF EXISTS clc.clipped_bretagne;
CREATE TABLE clc.clipped_bretagne AS
SELECT clc.gid as clcgid,c.gid, clc.the_geom FROM clc.clc00_v2_europe clc INNER JOIN ccm21.catchments c
        ON  ST_Intersects (c.the_geom,clc.the_geom)
        WHERE c.wso_id IN (SELECT wso_id FROM france.wso WHERE area='Bretagne')
        AND substring(code_00 from 1 for 1)='1';
ALTER TABLE clc.clipped_bretagne add column id serial PRIMARY KEY;

-- la requete globale
SELECT intersected.clcgid, intersected.gid, clipped_geom
FROM (SELECT clc.gid as clcgid, c.gid, ST_Intersection(clc.the_geom, c.the_geom) AS clipped_geom
        FROM  clc.clc00_v2_europe clc INNER JOIN ccm21.catchments c
        ON  ST_Intersects (c.the_geom,clc.the_geom)
        where substring(code_00 from 1 for 1)='1' )  AS intersected;