擅长:python、mysql、java
<p>如果要进行聚合,可以使用<a href="http://docs.djangoproject.com/en/dev/topics/db/aggregation/#topics-db-aggregation" rel="noreferrer">aggregation features of the ORM</a>:</p>
<pre><code>from django.db.models import Count
Members.objects.values('designation').annotate(dcount=Count('designation'))
</code></pre>
<p>这将生成一个类似于</p>
<pre><code>SELECT designation, COUNT(designation) AS dcount
FROM members GROUP BY designation
</code></pre>
<p>结果会是</p>
<pre><code>[{'designation': 'Salesman', 'dcount': 2},
{'designation': 'Manager', 'dcount': 2}]
</code></pre>