title: IS NULL versus <> 1 SQL bit
body: <p>I have a bit column on a table in a SQL Server 2012 database. </p>
  
  <p>I am trying to retrieve all the rows where this bit column is either <code>NULL</code> or NOT TRUE. </p>
  
  <p>This query does not bring back what it should: (returns 0 rows)</p>
  
  <pre><code>Select * 
  from table 
  where bit_column_value &lt;&gt; 1
  </code></pre>
  
  <p>This query brings back the correct rows: </p>
  
  <pre><code>Select * 
  from table 
  where bit_column_value IS NULL
  </code></pre>
  
  <p>Now, I'd be happy to use the second query, but my issue is that, in a similar query for another table, the reverse of the above is true, where the first way works, but the second way does not! </p>
  
  <p>Could someone assist in explaining what the difference is in the above? I have specifically updated the relevant bit columns to be NULL and this does not change the results. (Thought maybe there was a difference between "Empty" and <code>Null</code> values. </p>
  
  <p>Thanks in advance for any explanations.</p>