title: Excel formula that returns sum based on categorical and date data from 2 columns?
body: <p>I have a dataset in excel that looks like this: </p>
  
  <pre><code>Supplier    Date          QTY
  A           03/02/2018    10
  A           05/01/2018    15
  A           08/06/2018    30
  B           02/01/2018    20
  B           04/01/2018    50
  B           08/01/2018    40
  B           08/15/2018    50
  B           10/01/2018    60
  C           03/09/2018    25
  C           04/08/2018    25
  C           05/20/2018    25
  </code></pre>
  
  <p>And I want to make a spreadsheet that allows the user to enter start and end dates and the Supplier name and be able to see a total quantity of items received in that time period from that supplier.</p>
  
  <p>I've tried using a combination of VLOOKUP and SUM, but I've only been able to get the first result of the quantity associated with that supplier to return. I understand that this is the nature of VLOOKUP--to only return one value. I'm pretty new to Excel so I just don't really even know which function(s) would be best to use in this scenario.</p>
  
  <p>Example Output:</p>
  
  <pre><code>Enter Supplier: "B"
  Enter Start Date: "03/01/2018"
  Enter End Date: "09/01/2018"
  
  Items Received: 140
  </code></pre>