title: SELECT FROM table WHERE lang = :preferred OR lang = :default
body: <p>I have a simple table with a language variable and a content field.</p>
  
  <pre><code>------------------------
  |  lg    |   content   |
  ------------------------
  |  en    |  Hello      |
  ------------------------
  |  es    |  Hola       |
  ------------------------
  </code></pre>
  
  <p>I can't be sure that I have the Spanish language in this table so I simply need to select from the table where the value is either <code>'es'</code> or <code>'en'</code>. I have been researching and found SQL <code>ISNULL()</code>, <code>NVL()</code>, <code>IFNULL()</code> and <code>COALESCE()</code> Functions. I have been looking at nested <code>IF ELSE</code> SQL <code>SELECT</code> statements, but I really need to know how is the simplest way to achieve this?</p>