title: How do I modify a MySQL column to allow NULL without specifying its data type?
body: <p>I have a table in mysql and I want to alter a table to allow a column to be null.</p>
  
  <p>When I do describe on my mysql table, I see these things in mysql workbench:</p>
  
  <pre><code>Field       Type        Null        Key     Default     Extra
  </code></pre>
  
  <p>I want to set <code>Null</code> field as <code>YES</code> for a particular column. Here is how I am trying which works fine but do I need to provide its data type while setting DEFAULT to NULL?</p>
  
  <pre><code>ALTER TABLE abc.xyz CHANGE hello hello int(10) unsigned DEFAULT NULL;
  ALTER TABLE abc.xyz CHANGE world world int(10) unsigned DEFAULT NULL;
  </code></pre>
  
  <p>Is there any other way by which I can just pick column name and set default to NULL instead of using its data type as well? I don't want to provide <code>int(10)</code> while setting its default to NULL.</p>