That depends. What kind of database, and how are you accessing it?
Basically, open a connection on the SQL database, then open a recordset on the transaction table, declare enough variables to hold all the information you want to pass, then get the info, mostly like this:
Dim sOldFName, sNewFName As String
sOldFName = Me.FName.OldValue
sNewFName = Me.FName.Value
Then pass the values to the recordset using AddNew and Update.
Exact code depends on ADO v. DAO, and how you are referencing the database, either ODBC or Provider.