擅长:python、mysql、java
<p>使用带有<code>annotate</code>的多个聚合时有一个警告:</p>
<blockquote>
<p>Combining multiple aggregations with <code>annotate()</code> will yield the wrong
results because joins are used instead of subqueries.
For most aggregates, there is no way to avoid this problem...</p>
</blockquote>
<p>而且,与<code>Count</code>的聚合不同,<code>Sum</code>不采用可以帮助重复数据消除的<code>distinct</code>参数。如果你想得到正确的结果,我想你应该保留不同的查询。在</p>
<p>见<a href="https://docs.djangoproject.com/en/1.11/topics/db/aggregation/#combining-multiple-aggregations" rel="nofollow noreferrer">Combining multiple aggregations</a>。在</p>