title: MySQL Delete String and everything behind that string
body: <p>If I am honest, I saw many answers but I don't quite get it. </p>
  
  <p>I have a column that contains the hashtag character <code>#</code> and I need to delete it and everything behind it. There is only one <code>#</code>. I have tried the following:</p>
  
  <pre><code>UPDATE my_table
  SET my_col = SUBSTRING_INDEX(my_col, '#', -1)
  </code></pre>
  
  <p>But it didn't work.</p>
  
  <p>Is that possible? Thank you in advance.</p>