[postgis-users] Using Trigger function to manipulate coordinates

[Frank Koormann]

* Broun Uganda <tekuganda at hotmail.com> [070621 11:56]:
>    I wrote the following filter for taking coordinates from the_geom to my
>    point_x & point_y columns but it is giving errors. Could anybody be of
>    help?
>    The Trigger is thus:
>    CREATE FUNCTION calc_point() RETURNS "trigger"
>        AS 'BEGIN
>    NEW.point_x = NEW.the_geom[0];
>    NEW.point_y = NEW.the_geom[1];

This should be something like 

    NEW.point_x = ST_X(NEW.the_geom);
    NEW.point_y = ST_Y(NEW.the_geom);

or on older PostGIS installations 

    NEW.point_x = X(NEW.the_geom);
    NEW.point_y = Y(NEW.the_geom);

HTH,

        Frank

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