title: DB2 Select where not equal to string that is NULL
body: <p>I have <code>COLUMN1 CHAR(1)</code> in <code>MYTABLE</code> where all rows are <code>NULL</code> and here is my sql query:</p>
  
  <pre><code>SELECT COLUMN1 FROM MYTABLE WHERE COLUMN1 != 'A'
  </code></pre>
  
  <p>it returns nothing because all rows have <code>NULL</code> in <code>COLUMN1</code>. I suppose it should return everything. How do I make it work? I don't wanna use </p>
  
  <pre><code>COALESCE(NULLIF(COLUMN1, ''), '*')
  </code></pre>
  
  <p>because it slows down the query. Is there any other alternatives?</p>