title: Replace empty cells with NULL values in large number of columns
body: <p>I have SQL table that has a large number of columns. For some reason, some columns have empty cells instead of NULL cells. I would like to make all empty cells in all the columns to be NULL.</p>
  
  <p>I know that the way to go for a single column is:</p>
  
  <pre><code> UPDATE your_table SET column = NULL WHERE column = ''
  </code></pre>
  
  <p>However, I am not sure how to execute a similar logic efficiently for all columns without having to write the column names one by one.</p>
  
  <p>Thanks,</p>