title: Filter rows by value1, if not use the other - Oracle
body: <p><strong>Column 1 &quot;Letter&quot;:</strong> A, B, C
  <strong>Column 2 &quot;Name&quot;:</strong> Apple, Boat, Cat</p>
  <p>I need a query to get the name value if the letter value equal to A. In case that no A, so return the name for B. So, I need to get one record at the end.</p>
  <p>Please help</p>