Adding rows based on common field names between two tables?

[CharlesCurtin]

So I'm dealing with building parcel data from two different years. I need to compare their land use for the two years. I joined the tables based on the unique ID of assessor parcel number (APN). For the records that didn't match (parcels sometimes get subdivided between years with new developments), I did a spatial join and now have a separate feature class from the spatial join where the APNs don't match. I'm trying to join these two tables back together but can't figure out how. My fields are APN_19, APN_16, Landuse_19, Landuse_16. Basically, I just want to add the rows with the unmatched APN's back into the greater table with all the parcels considering that the fields are the same. If it helps, the OID field is intact between the two tables, so maybe some sort of sequential join would work if that's a thing? For example, out of 5 parcels, 1,3,5 matched based on APN. The spatial join feature class still has the OID of 2 and 4 intact.

[DavidPike]

I've read this several times and would find a few pictures very helpful.

[CharlesCurtin]

an example of two rows from the table with matching APNs and the table where the APNs are different. For the table with different APNs, the polygons from 2016 were likely subdivided into more parcels for 2019, so the 2019 APN represents a polygon with its center in the 2016 polygon. I just want to join these two tables together 

[DavidPike · Accepted solution]

Oh right, Merge (Data Management) or Append.