Hi Steve, 

Pretty much have comprehensively searched the web for this issue as well as having already read the link you suggested. I'm creating a new thread just to...

Turns out it was a lot simpler - always the case! 

In the data flow task the flat file destination had the the check box 'overwrite data in the...

I was thinking along these lines. Which function do you suggest - merge, merge join or union all?

And should the function be used after the derived column transformations...

What is currently set up is the following.

Data flow task:
1. Import file from source (all files in a single folder). 
2. Derived column transformations. 
3. File...