What is the difference between Insert or Update and Update or Insert
Insert or Update : First tries to insert a record, but if a record with a matching primary key already exists, instead updates that record.
Update or Insert : First tries to update a record with a matching primary key, but if none already exists, instead inserts the record.
From a results point of view , there are no differences between the two, nor are there significant performance differences. In general , choose the action that matches what you expect to be more common: Insert or Update if you think there are more inserts than updates, Update or Insert if you think there are more updates than inserts.