title: How do I find the highest common number for each group in SQLite?
body: <p>Here is my table example:</p>
  
  <pre><code>LETTER  NUMBER
  a   1
  a   2
  a   4
  b   1
  b   2
  b   3
  c   1
  c   2
  c   3
  d   1
  d   2
  d   3
  e   1
  e   2
  e   3
  </code></pre>
  
  <p><br>
  The result I want:</p>
  
  <pre><code>LETTER  NUMBER
  a   2
  b   2
  c   2
  d   2
  e   2
  </code></pre>
  
  <p>The highest number that matches an 'a' is 4, while it's 3 for the other letters. However, the highest letter they all have in common is 2. That is why the result table has 2 for the NUMBER.</p>
  
  <p>Does anyone know how I can accomplish this?</p>