title: Conversion failed when converting the nvarchar value 'S' to data type int
body: <p>I was playing with SQL. AdventureWorks2012 database, table: Production.Products.</p>
  
  <p>I was trying to get products which have <code>color</code> black and: either have <code>weight</code> NULL or their <code>size</code> and <code>listPrice</code> is above some value.</p>
  
  <p>Here is query</p>
  
  <pre><code>SELECT * 
  FROM AdventureWorks2012.Production.Product 
  WHERE (Color = 'Black') 
    AND ((ListPrice &gt; 300 AND Size &gt; 60) OR Weight IS NULL)
  </code></pre>
  
  <p>But this is the error I get</p>
  
  <blockquote>
    <p>Conversion failed when converting the nvarchar value 'S' to data type int.</p>
  </blockquote>
  
  <p>Can anyone clarify what I did wrong?</p>