汉景源的博客

1. 求出裁剪后的图斑

SELECT res.*, 
	st_area(res.wkt) as real_area, 
	st_astext(res.wkt) as real_wkt
FROM (
		SELECT jb.*,
		ST_Intersection(jb.geom, 
						st_geomfromtext('POLYGON ((113.14665136337281 28.156513464450835, 113.14883825778962 28.154443204402924, 113.14498932361603 28.153830873966218, 113.14665136337281 28.156513464450835))',4490)
			) 
		AS wkt
		FROM public.jbntbhtb as jb
		WHERE 
			ST_Intersects(jb.geom, 
						  st_geomfromtext('POLYGON ((113.14665136337281 28.156513464450835, 113.14883825778962 28.154443204402924, 113.14498932361603 28.153830873966218, 113.14665136337281 28.156513464450835))',4490)
				)
	) 
AS res;