此操作失败，因为键已经存在。

This operation fails, because the key already exists.

youdao

如果操作失败，那么存储过程将中止。

If the action fails, the stored procedure is aborted.

youdao

当操作失败的时候V8会返回一个空句柄。

V8 returns an empty handle if an operation did not succeed.

youdao

What this is is learning the relationships between what you do and how successful or unsuccessful they are, learning what works and what doesn't.

操作性条件作用,是在学习行为与成功,或失败程度之间的关系，学习什么行为起作用,什么行为不起作用。

耶鲁公开课 - 心理学导论课程节选