topic Re: Symbolize a layer based on it's related table (1:M relationship class) in Spatial Data Science Questions

Symbolize a layer based on it's related table (1:M relationship class)

NickAlexandrou1 — Thu, 05 May 2016 19:32:55 GMT

I have a layer of polygons joined by a relationship class to a table by Field = DistrictIDNumber

The Table has multiple entries for each polygon so it is a one to many relationship.

Is there any way to symbolize the polygons based on count of related entries?

Lets say they are number of hydrants and the polygons are districts within a county. Can I symbolize the polygons, in graduated colors, based on the number of hydrants reported in that district?

I can't use the actual point data of the table.

I hope this made sense. I'm open to programming solutions if anyone knows of anything. Thanks.

Re: Symbolize a layer based on it's related table (1:M relationship class)

JayantaPoddar — Thu, 05 May 2016 20:12:17 GMT

Check this thread. Joe Borgione has the answer

How to calculate number of related records

Create a summary table of the relate-field of Table B. This will give you a two column table: Relate-Field and Count.
If you want the count value in table A, add a new field called A_Count (or what ever) and then join the summary table to table A via the relate-field; calc A_Count = SummaryTable_Count and you'll be good to go.

Using the count field (after joining), you can symbolize the layer.

Re: Symbolize a layer based on it's related table (1:M relationship class)

NickAlexandrou1 — Thu, 05 May 2016 20:16:33 GMT

Oh that's nice. Thanks!