title: MySQL - Which way is better to check if a column is null or empty
body: <p>Well, when we are going to select records which include nothing in a column, we can use this:</p>
  
  <pre><code>SELECT * FROM my_table WHERE NULLIF(my_column, '') IS NULL;
  </code></pre>
  
  <p>But, in most cases, I see developers use this:</p>
  
  <pre><code>SELECT * FROM my_table WHERE my_column IS NULL OR my_column = ''
  </code></pre>
  
  <p>Is there any preference between these two? (e.g. performance, default support, version support, etc.)</p>
  
  <p>If yes, please explain.</p>