[postgis-users] FW: Support in ST_ConvexHull syntax

Gery . gamejihou at hotmail.com
Wed Oct 19 06:59:06 PDT 2011



Thanks, I added it but get the following message: new row for relation "unaprueba" violates check constraint "enforce_geotype_geom"

The idea is to create just one polygon based on the points distribution, so I don't need multipolygon, is it right?


----------------------------------------
> From: gamejihou at hotmail.com
> To: postgis-users at postgis.refractions.net
> Subject: Support in ST_ConvexHull syntax
> Date: Wed, 19 Oct 2011 13:23:28 +0000
>
>
>
> Hello,
>
> After reading a while, I don't get the polygon from my points table (splitbeam_point) I think it is possible through the following script:
>
> DROP TABLE testone;
> CREATE TABLE testone(
> ID INT
> );
> SELECT AddGeometryColumn('public', 'testone', 'geom', 4326, 'POLYGON', 2);
> CREATE INDEX testone_geom ON testone USING GIST ( geom );
> INSERT INTO testone SELECT ST_ConvexHull(ST_Collect(geom)) AS testone_geom FROM splitbeam_point GROUP BY ID;
>
> I get this error message:  column "id" is of type integer but expression is of type geometry
>
> and after I insert ::numeric,4 in the ST_ConvexHull statement, I get: ERROR:  cannot cast type geometry to numeric
>
> How can I circumvent this error?
>
> Any support is very welcome, thanks,
>
> Gery
>
 		 	   		  


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