title: Finding records that occur most commonly together in SQL
body: <p>I have a table of ingredients:</p>
  
  <pre><code>ing_id, ing_name
  1      , ing1
  ...
  </code></pre>
  
  <p>a table of recipes:</p>
  
  <pre><code>rec_id, rec_name
  1     , rec1
  ...
  </code></pre>
  
  <p>and a table showing the connection between the two:</p>
  
  <pre><code>id, ing_id, rec_id
  1,  1, 1
  2,  1, 2
  3,  2, 1
  4,  3, 3
  ...
  </code></pre>
  
  <p>How can I find the ingredients that most commonly appear in the same recipe?</p>