Here is a picture explaining what I have and what I'm looking for.
Tables and data describing the question.
This originally seemed like a very simple update query but it has proven I really don't understand how the query works. Can someone please explain the SQL I would need to move all the data from tblImport.Addtl_Initiator to the respective blanks under tblEntries.Initiator, and the data from tblImport.Addtl_Date_Initiated to the respective blanks under tblEntries.Date_Initiated? Essentially just moving the data to the left one column, but in a different table.
Additional information: There is a unique ID field on each of the tables not shown in the picture.
Try it with Nz.
UPDATE tblentries INNER JOIN tblimport ON tblentries.eid = tblimport.eid AND tblentries.initiator = tblimport.initiator AND tblentries.date_initiated = tblimport.date_initiated SET tblentries.initiator = nz(tblimport.initiator, tblimport.addtl_initiator), tblentries.date_initiated = nz(tblimport.date_initiated, import.addtl_date_initiated)
This link might also be helpful: coalesce alternative in Access SQL