topic Re: Delete Feature Class if no Geometry Exists in Geoprocessing Questions

Delete Feature Class if no Geometry Exists

StuartBlumberg — Tue, 29 May 2012 20:29:09 GMT

Hi,

I have a model using ModelBuilder that extracts data from an SDE database into a new personal geodatabase that the user creates. I don't want to include any feature classes that have no geometry. Is there a way to check all feature classes for geometry and delete the ones without using ModelBuilder? The tool also extracts tables from spatial features from the SDE, is there a way to check if data exists in these tables and if not then delete them? I am using ArcGIS 9.3.1. Thank you.

Re: Delete Feature Class if no Geometry Exists

MathewCoyle — Tue, 29 May 2012 20:40:23 GMT

You can use a where clause in your export of shapefield is null.

Re: Delete Feature Class if no Geometry Exists

StuartBlumberg — Tue, 29 May 2012 21:04:05 GMT

Mathew,

I am using "feature class to feature class" tool to export the layers from SDE to the geodatabase. Do I need to add something (null) to the 'expression' box inside the "feature class to feature class" tool to omit the layer if it has no geometry? Thanks for your help.

Re: Delete Feature Class if no Geometry Exists

MathewCoyle — Tue, 29 May 2012 21:09:48 GMT

Something like this. Where SHAPE.AREA is the name of your shape field to test if it is null.

"SHAPE.AREA IS NOT NULL"

Re: Delete Feature Class if no Geometry Exists

StuartBlumberg — Wed, 30 May 2012 12:46:52 GMT

Mathew,

using that expression does not seem to prevent the feature class from being created. It still creates the feature class with empty geometry. Is there another approach? Thanks.

Re: Delete Feature Class if no Geometry Exists

MathewCoyle — Wed, 30 May 2012 13:24:36 GMT

Is your geometry null or zero? You'll have to query based on the particulars of your data.

Re: Delete Feature Class if no Geometry Exists

StuartBlumberg — Wed, 30 May 2012 13:26:36 GMT

Mathew,

The feature class is completely empty, there are no rows in the attribute table. Thanks.

Re: Delete Feature Class if no Geometry Exists

MathewCoyle — Sat, 11 Dec 2021 18:47:21 GMT

An empty feature class is very different than a feature class with no geometry. If you want to completely avoid exporting an entire feature class if it has no rows, use the get count method.

count = arcpy.GetCount_management(fc)
if count > 0:
    #export

Re: Delete Feature Class if no Geometry Exists

StuartBlumberg — Wed, 30 May 2012 13:49:17 GMT

I see, I was using the wrong term, thanks for clarifying! Unfortunately we are still on 9.3.1 so Arcpy will not work, is there a way to do it otherwise using sql? Thanks.

Re: Delete Feature Class if no Geometry Exists

MathewCoyle — Sat, 11 Dec 2021 18:47:24 GMT

Get Count is available for 9.3 as well. It just requires slightly different commands I believe.

Example

result = gp.GetCount_management("roads")
count = int(result.GetOutput(0))

Re: Delete Feature Class if no Geometry Exists

StuartBlumberg — Wed, 30 May 2012 14:02:21 GMT

I may be a bit slow when it comes to programming, where do I need to apply this code? Do I need to a create a python script? Can I put this into model builder? How could I set it up to delete all empty feature classes in a geodatabase? Thanks so much for your help and patience.

Re: Delete Feature Class if no Geometry Exists

MathewCoyle — Wed, 30 May 2012 14:15:37 GMT

In the link I posted there is an example of it being used in a model work flow. You can use the same methodology to delete them by using the delete tool.

Re: Delete Feature Class if no Geometry Exists

StuartBlumberg — Thu, 31 May 2012 12:21:09 GMT

Great! That did the trick, thank you so much!