title: concatenate strings with atomic update in peewee using sqlite db
body: <p>I would like to update a text field in an sqlite database created using the peewee python library. Specifically I would like to use peewee's atomic updates something like:</p>
  
  <pre><code>query = Table.update(textfield = Table.textfield + 'string').where(some condition)
  
  query.execute()
  </code></pre>
  
  <p>This type of update works fine for numeric fields but not for text fields.  I'm guessing there may be a way to do this with the sqlite || operator, but as sql in general is somewhat new to me I am unable to figure it out.</p>