topic Using iterator to create new fields in a table based on values in a different table in Geoprocessing Questions

Using iterator to create new fields in a table based on values in a different table

SteveH — Tue, 25 May 2021 22:24:24 GMT

I have a table with a list of threatened species. Using model builder I want to add fields to a different layer - one field for every unique species value. The list will vary and the number of species will vary too so I can't create a predefined list of new fields.

Is this possible?

Re: Using iterator to create new fields in a table based on values in a different table

DanPatterson — Tue, 25 May 2021 22:40:46 GMT

Add Fields (multiple) (Data Management)—ArcGIS Pro | Documentation

just make sure your field names comply with geodatabase field specifications (skip shapefiles/dbase altogether). (no spaces in name, keep them short etc etc).

It would be simpler if you just pre-parsed the list.

What does your table of threatened species look like? are the species in one field in a table?

What type of fields do you want (text, boolean, integer, etc).

There are simple ways to get the unique names from data.

Modelbuilder seems like overkill unless you are going to repeat this endlessly

Back to you for details...

Re: Using iterator to create new fields in a table based on values in a different table

SteveH — Tue, 25 May 2021 23:28:43 GMT

Thanks Dan, this is a small part of a much larger model I'm building in Model builder. I'm kind of new to iterators so I'm not sure how to set this up.

All of the species are in a single field in a point file and I would prefer to create Text fields named ThrSpec_1, ThrSpec_2 etc in a Polygon file of land parcels and populate the fields of selected records with the relevant species name.

Does that make sense?

Thanks, Steve

Re: Using iterator to create new fields in a table based on values in a different table

DanPatterson — Wed, 26 May 2021 01:44:32 GMT

Getting closer...

The first thing to ask, is did you do a spatial join of the polygon layer to the points to find out what which polygon the points belong to?

Second, there isn't going to be the same number of threatened species in each polygon I suspect, so you need to know ahead of time how many fields to create or a plan to deal with this.

Third, do you just want the species name or the species name and number to be recorded if there was more than one recording? (thinking ahead).

Final table layout????

PolyID, ThrSpec_1, N_1, ThrSpec_2, N_2, ThrSpec_3, N_3, .... ThrSpec_N, N_n

1 parrot, 1000, budgie, 5, crow, 300

2 parrot, 3, budgie, 0, crow, 0

3 parrot, 0, budgie, 10, crow, 0

OR!!!

PolyID, Parrot, Budgie, Crow, Turkey_Vulture,

1 1000, 5, , 300, 10

2 3, 0, 0, 1000

3 0, 10, 0, 0

OR !!!!

something completely different?

Re: Using iterator to create new fields in a table based on values in a different table

SteveH — Wed, 26 May 2021 10:57:05 GMT

Joins seem a bit clunky in model builder so I was going to do an iterative select by location for each species. I don't need species counts, this is just a presence /absence. So reading down Column ThrSpec_1 may read Devil, null, null, Devil, Devil etc. ThrSpec_2 may be null, Quoll, Quoll, null etc...

Part of the reason I wanted to do this iteratively was to create the columns on the fly as needed - select unique species value 1, create column, select parcels, fill values. Repeat for unique value 2. etc. I just don't know how to use an iterator to carry out a task on a different layer.