August 2022
Beginner to intermediate
463 pages
9h 22m
Chinese
Content preview from Tableau Prep即学即用
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249
空值处理
现在你应该看到这两个字段合并到了一起，其中一列的空值被另一列的相应值取代。
最终的数据集如图
27-12
所示。
图
27
-
12
：合并后的数据集的结果
Null
（空值）可能是令人沮丧的，但希望本章能帮助你了解你的选择，什么时候可
以保留空值，以及何时、如何删除或替换它们。
27.4
小结
空值是指数据集中没有值的情况。在很多情况下，它们的存在对于正确地分析数据
是必要的。然而，在需要删除或更改空值的地方，有很多不同的技术可供选择。为
了选择合适的技术，需要考虑清楚你的行为对后续分析所产生的影响。
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