title: What happens if you declare an SQLite column PRIMARY KEY + UNIQUE?
body: <p>SQLite's documentation says:</p>
  
  <blockquote>
    <p>A UNIQUE constraint is similar to a PRIMARY KEY constraint, except that a single table may have any number of UNIQUE constraints.</p>
  </blockquote>
  
  <p>What I'm wondering is, if I declare something like:</p>
  
  <pre><code>CREATE TABLE Example (
    id INTEGER PRIMARY KEY UNIQUE);
  </code></pre>
  
  <p>Does SQLite create two indexes or one? Is the behavior different if I'm not using the rowid (i.e. if the column was <code>id TEXT PRIMARY KEY UNIQUE</code>)?</p>
  
  <p>I realize the simplest thing to do is just remove <code>UNIQUE</code> but I'm curious what effect this will have.</p>