I have a Microsoft Access database with columns MTRS, Lat_Y, and Lon_X filled with data all cells, 680,000 rows. I have a second similar Access database with data for MTRS but empty cells for Lat_Y, and Lon_X, 1600 rows. How do I fill the Lat_Y and Lon_X cells in the second smaller database for matching values of MTRS? I typically use OleDbConnection in C# to manipulate Access databases. I am weak on Access queries. I also have ArcGIS and QGIS but have limited experience with these.