title: How do I sum one column within a grouping of another column?
body: <p>This is my problem:</p>
  
  <pre><code>NAME    DATE           PRESENTS
  bob     march 3 2011      1
  bob     june 6 2008       2
  bob     jan 3 2012        3
  mary    feb 14 1986       4
  mary    april 10 2001     5
  mary    jan 3 2012        6
  kate    march 3 2011      7
  kate    jan 3 2012        8
  kate    oct 9 2013        9
  celia   march 3 2011     10
  celia   feb 14 1986      11
  celia   july 4 2011      12
  celia   jan 3 2012       13
  celia   feb 14 1991      14
  </code></pre>
  
  <p>So the goal is that we add the amount of presents Kate and Celia got on the same days if they received any at all on those days.    </p>
  
  <p>What I need to do is kind of like this, except with a much bigger data set. The size of the data set is probably around 100,000 entries. </p>
  
  <p>I need the answer in SQL, or as an Access 2003 query.   </p>