title: How to use Unique Composite Key
body: <p>I have a table  </p>
  
  <pre><code>Item(ItemName*, ItemSize*, Price, Notes)
  </code></pre>
  
  <p>I was making composite key of (ItemName,ItemSize) to uniquely identify item. And now after reading some answers on stackoverflow suggesting the use of UNIQUE i revised it as  </p>
  
  <pre><code>Item(ItemID*, ItemName, ItemSize, Price, Notes)
  </code></pre>
  
  <p>But How to apply UNIQUE constraint on ItemName and ItemSize</p>
  
  <p><em>please correct if there is something wrong in question</em></p>