擅长:python、mysql、java
<p>您必须进行从<code>find</code>返回的<code>distinct</code>调用<a href="http://api.mongodb.org/python/current/api/pymongo/cursor.html#pymongo.cursor.Cursor.distinct">on the cursor</a>,而不是在集合上:</p>
<pre><code>tags = db.mycoll.find({"category": "movie"}).distinct("tags")
</code></pre>