title: how to create calculated field in mysql?
body: <p>i have a table like below:</p>
  
  <pre><code>create table info (username varchar(30),otherinfo varchar(100));
  </code></pre>
  
  <p>now i want to alter this table to have new field and this field has to have default value as </p>
  
  <pre><code>md5(username)
  </code></pre>
  
  <p>something like below:</p>
  
  <pre><code>alter table info add NewField varchar(100) default md5(username);
  </code></pre>
  
  <p>how to do so?<br>
  Thanks for your help</p>