Hi, Everybody!
I'm working in ArcGIS Online/Pro/ArcMap. I have 10 years of water sampling data from multiple sampling stations. Stations have between 2 and 50 sampling events of 3 different types (Bacteria, Macroinvertebrates, Chemistry).
I have a GDB with a feature layer of Sampling Station points and 3 related tables (Bacteria, Macro, Chemistry). I want to symbolize the Sampling Stations by size, based on the number of sampling events at each location. I would have three copies of the Sampling Station layer (Bacteria, Macro, Chemistry) to display this.
Though I see several examples of changing the style based on attributes with an Arcade Expression, none of them seem available to me. I cannot access feature sets, and cannot seem to access table records (or the overall related table) from the functions available in the Arcade expression builder associated with the Change Style dialog.
How can I count the records at each station from a related table and set my symbol sizes from that count? As shown in the attached image, I can "see" the related record count in the feature layer's attribute table. How do access those numbers in "()" and symbolize my layer based on that?
Thanks for any help!