I am using ArcMap 10.6.
I am joining a table of public housing developments to a parcel map layer, and there is a one-to-many relationship between the parcels and developments: multiple buildings may occupy any given parcel, and each has its own row of attribute data, such as number of housing units. I'm hoping to aggregate the data from the housing developments to the parcel layer, e.g. so that I can display the sum of all housing units contained in each parcel.
I could do this quite easily with an Excel pivot table or with the R aggregate() function, but if possible I'd like to avoid bringing in a whole new table (i.e. with the aggregated data) and keep the relationship within the geodatabase, which I'm less sure how to do.
In very simplified terms, my data looks something like this:
And I'd ultimately like the parcel layer's attribute table to look like this:
How I might accomplish this with a relationship class/ArcMap relate?
It's not the end of the world if I have to aggregate the data outside of ArcGIS and bring in a separate table, but I feel like that should be avoidable, and I'm curious as to how.