Combine model fields
<p>I would like to add a field to a read-only database. So, I would like to create a dummy database of the form;</p>

<pre><code>class ReadOnly(models.Model):
    first =  models.CharField(db_column='First')
    second = models.CharField(db_column='Second')

class ExtraStuff(models.Model):
    first =  models.CharField(db_column='First')
    second = models.CharField(db_column='Second')
    combined = first+second
</code></pre>

<p>I have used the @property but as I cannot combine properties and filters I feel like this is a better solution. However, I am out of ideas for how to achieve this.</p>