title: django model field: Why default value not working?
body: <p>When I create a new row in my PG commander<br>
  I let <code>small_price</code> empty because I thought I set a default : 0</p>
  
  <pre><code>small_price = models.IntegerField(default=0)  
  </code></pre>
  
  <p>But when I saved It has an alert :  </p>
  
  <pre><code>Reason: null value in column "small_price" violates not-null constraint
  </code></pre>
  
  <p>Why the default not work??
  Do I still need to type 0 when create row??  </p>