August 2022
Beginner to intermediate
463 pages
9h 22m
Chinese
Content preview from Tableau Prep即学即用
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｜
205
创建附加数据
图
22
-
7
：准备工作中的一个联合步骤
22.3.3
数据集支撑
最后一种添加行的技术──
Scaffolding
（支撑），通常用于在需要记录值（即使是
空值或零值）的情况下填充缺失的日期或记录。这涉及将核心数据集添加到支撑中，
支撑中包含了所有你需要的记录。支撑是一种比较复杂的技术，所以第
39
章用了整
整一章专门介绍它。
22.3.4
连接数据集
虽然数据集支撑涉及使用数据连接操作，但正如刚才所描述的，你也可以直接使用
连接来创建额外的行。虽然这样做有产生重复数据的风险，但对于某些应用场景来
说是有益的。例如，如果你有一个区域级的销售对象的数据集和另一个该区域内的
商店列表的数据集，可以通过将这些数据集连接在一起来分离这些商店的对象。数
据集的粒度不同，意味着粒度较小的数据集（即销售对象）将在各门店之间重复。
然后，通过计算可以正确地将对象分配到各个门店。
22.4
小结
本章所涉及的许多技术在本书的其余部分都有更详细的描述。还有其他方法可以在
数据集中创建额外的列或行，但本章所涉及的这些技术可能是你所要使用的主要技
术。虽然有可能会因为预先计算一些度量而在一定程度上失去数据集的灵活性，但
在数据准备阶段，这样做可以为那些缺乏技术知识或技能、无法自己处理这项任务
的最终用户节省数小时的研究和工作时间。
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I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.