title: How to insert data in database, without inserting duplicates? (vb.net)
body: <p>I've been searching on the net, and this query should work: </p>
  
  <pre><code>INSERT INTO Groep(Naam) SELECT ? WHERE NOT EXISTS (SELECT * FROM Groep Where Naam=?)
  </code></pre>
  
  <p>but it doesn't.. I get an <code>OleDbException</code>: </p>
  
  <blockquote>
    <p>Incorrect syntax near the keyword 'DEFAULT'</p>
  </blockquote>