Upate only new rows to existing table in ADF Dataflow

Hi all,

I have a challenge of updating missing data for specific day into a table

I have a workflow built that daily reads data from blobstorage and sink into azure sql db. 

Now I need to add a conditions for when we have missing data for other days, for example: let's say yesterday we had missing data that wasn't sent and they were sent today and the challenge is that this file comes with full data from yesterday meaning that my table will already contains records of yesterday. 
The challenge is to update only the NEW records missing from that day or to delete the records for that day then upload the new file with the missing records.

I was trying to use ALTER ROW which seems doable but I could not find a way to read the file name and capture the day.

Any thoughts?

Thanks in advance

Regards,

Fab