title: Parsing excel sheet in C#, inserting new values into database
body: <p>I am currently working on a project to parse an excel sheet and insert any values into a database which were not inserted previously.  The sheet contains roughly 80 date-value pairs for different names, with an average of about 1500 rows per pair.  </p>
  
  <p>Each name has 5 date-value pairs entered manually at the end of the week.  Over the weekend, my process will parse the excel file and insert any values that are not currently in the database.</p>
  
  <p>My question is, given the large amount of total data and the small amount added each week, how would you determine easily which values need to be inserted?  I have considered adding another table to store the last date inserted for each name and taking any rows after that.</p>