[postgis-users] identifying blank geometry fields

Stephen Woodbridge woodbri at swoodbridge.com
Mon Nov 23 11:30:13 PST 2009


Did you try:

select count(*) from yourtable where the_geom is null;

delete from yourtable where the_geom is null:


-Steve

Bob Hume wrote:
> 
>            I loaded a shapefile into my Postgresql/Postgis table. I'm 
> trying to put data in some records that appear to have no data and 
> eventually delete records with no geometry data. One problem is that I 
> can't seem to identify records with no geometry data.  If I review the 
> the_geom field for all records, there are several records that seem to 
> be blank.  Nothing is shown in the field when I do a listing of all 
> fields and all records. However, using ST_Npoints shows, for example, 
> 438 points for the “blank” record and St_IsValidReason says that it is a 
> Valid Geometry.  St_GeometryType says it is ST_MultiString.  However, 
> St_AsEWKT for the record is blank. It doesn't show  any coordinates like 
> the other records that do have data in the the_geom field.  St_IsEmpty 
> shows "f" for all records, including the ones that are apparently empty.
> 
>            So, it seems that the geometry data is  missing, but it isn't.
> 
>            How can identify the records with apparently missing geometry 
> data?  Thanks for the advice.
> 
>   
> 
> 
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