title: Copy records from one table to another without duplicates
body: <pre><code>IF object_id('tempdb..#A')  IS NOT NULL DROP TABLE #A
  IF object_id('tempdb..#B')  IS NOT NULL DROP TABLE #B
  CREATE TABLE #A (fname varchar(20), lname varchar(20))
  CREATE TABLE #B (fname varchar(20), lname varchar(20))
  
  INSERT INTO #A
  SELECT 'Kevin', 'XP'
  UNION ALL
  SELECT 'Tammy', 'Win7'
  UNION ALL
  SELECT 'Wes', 'XP'
  UNION ALL 
  SELECT 'Susan', 'Win7'
  UNION ALL
  SELECT 'Kevin', 'Win7'
  
  
  SELECT * FROM #A
  
  INSERT INTO #B
  SELECT a.fname, a.lname FROM #A a
  WHERE a.fname NOT IN (SELECT fname from #B)
  
  SELECT * FROM #B
  
  DELETE FROM #B
  INSERT INTO #B
  SELECT a.fname, a.lname FROM #A a
  LEFT OUTER JOIN #B b ON a.fname = b.fname
  WHERE a.fname NOT IN (SELECT fname from #B)
  
  SELECT * FROM #B
  </code></pre>
  
  <p>Both of these examples copy all 5 records to the new table.</p>
  
  <p>I only want to see one unique fname so only one Kevin should show up.</p>
  
  <p>Why don't these work, or is there a better way to do it?</p>
  
  <p>It seems like such a simple thing.</p>