This is a consequence of there being no primary and foreign keys in CouchDB. There are no keys to base joins on.

因此 CouchDB 中没有主键和外键，没有基于连接的键。

youdao

My car that was under the porch sits outside the gate but I have no keys to take the injured to hospital. And no road I suppose.

我的车就停在门外的走廊里，但我没有钥匙，无法将受伤者送往医院，可能也没有路，我想。

youdao

The car contained the paraphernalia of a growing number of suicides in Japan, although investigators were puzzled to find there were no keys in the ignition.

日本的自杀事件日趋增多，这辆车装着用于自杀的随身用具，但调查人员发现点火装置上并没有钥匙，这令他们迷惑不解。

youdao

So far, no oil from the Deepwater Horizon leak has been found near the Florida Keys.

VOA: standard.2010.07.05

What you can do is you can iterate keys, which gives you the keys in the dictionary, and then you can choose them, but there's no guarantee in the order in which you get keys.

你能做的就是迭代得到键，这样就可以得到字典中，所有的键并进行选择，但是键的顺序,是没有保证的。

麻省理工公开课 - 计算机科学及编程导论课程节选

Yes, that thin TranSleeve cover snaps on in a manner similar to a Type Cover, but there are no keys attached there.

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While those already in place should still work since existing keys will remain active, the developer forums are being set to read-only, no new keys are being issued and new partners are no longer being accepted.

ENGADGET

The keyboard is the one we uncovered last week, with no function keys, but a full row of Apple Keyboard-style actions.

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