title: SQl query on max summation
body: <p>I've got two tables</p>
  
  <p><strong>Unit</strong></p>
  
  <pre><code>Unit_id
  Unit_name
  Unit_cost
  </code></pre>
  
  <p><strong>Components</strong></p>
  
  <pre><code>Component_id
  Component_name
  Unit_id
  </code></pre>
  
  <p>They are linked together by <code>Unit_id</code>.</p>
  
  <p>I need the single <strong>Unit_name</strong> of the one unit that has the highest total cost (Unit.Unit_cost), with all of the Components linked to the Units table by the <strong>Unit_id</strong>.  Note I just need the <strong>Unit_Name</strong> only, not total cost.</p>
  
  <p>Would it be best to use a "Top(1)" in the query?  How would the query look?</p>