Check for the Mapping from a flat file

Hi Gurus,

I have a question

I have flat file source , the mapping is done for 10 columns

for example flat file has 10 columns i have mapped them to 10 columns in the database

if the flat file has only 7 columns instead of 10 my job fails is there a way to check if there are 10 columns and send an alert

  before getting loaded into the databse ?

thanks,