title: How do I drop 'NOT NULL' from a column in MySQL?
body: <p>A show create table command shows the following:</p>
  
  <pre><code>'columnA' varchar(6) NOT NULL DEFAULT '';
  </code></pre>
  
  <p>How do I modify that column so that the not null is removed?
  I need it to be:</p>
  
  <pre><code>'columnA' varchar(6) DEFAULT NULL;
  </code></pre>
  
  <p>I thought the following would work, but it has no effect:</p>
  
  <pre><code>ALTER TABLE tbl_name MODIFY columnA varchar(6) DEFAULT NULL;
  </code></pre>