PostGIS Cookbook - Second Edition

How to do it...

Now we need a geometry column to populate. By default, the geometry column will be populated with null values. We populate a geometry column using the following query:

SELECT AddGeometryColumn ('chp02','xwhyzed1','geom',3734,'POINT',2); 

We now have a column called geom with an SRID of 3734; that is, a point geometry type in two dimensions. Since we have x, y, and z data, we could, in principle, populate a 3D point table using a similar approach.

Since all the geometry values are currently null, we will populate them using an UPDATE statement as follows:

UPDATE chp02.xwhyzed1 
  SET the_geom = ST_SetSRID(ST_MakePoint(x,y), 3734); 

The query here is simple when broken down. We update the xwhyzed1 table and set the the_geom column ...