title: How to update all columns that are NULL to empty string?
body: <p>I want to update my table so that every column that has a value of NULL is updated to be and empty string.</p>
  
  <p>Currently I have the following query, but it would only update one column and I want to update all columns that are NULL to empty string.</p>
  
  <pre><code>UPDATE table SET column1='' WHERE column1 IS NULL
  </code></pre>