August 2022
Beginner to intermediate
463 pages
9h 22m
Chinese
Content preview from Tableau Prep即学即用
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｜
137
将数据集连接到一起
图
16
-
5
：查看连接的效果
此视图底部的
Summary of Join Results
（连接结果概要）列出了所产生的数据集中
的行数（连接结果），以及来自每个原始数据集中的数据行数。如果连接结果明显
高于任何一个输入数据集，则应检查连接是否创建了重复的或其他额外的行。确定
了使用哪种类型后，这些信息可以让你深入了解不同连接的潜在影响。要更改连接
类型，可单击界面中部
Join Type
（连接类型）区域的维恩图的不同部分。其中深灰
色阴影的区域都将包含在输出结果中。要想阻止维恩图的某个部分被返回，可再次
单击该部分以取消选择。
16.2
加入逻辑与术语
大多数的数据处理软件，包括
Prep
，都使用类似的逻辑和术语将数据集连接在一起。
然而，在
Prep
中把数据集连接在一起比在其他工具中要易用得多。
图
16-6
和图
16-7
展示了两个与销售相关的表格，我们可能要将它们连接在一起来
分析收入情况。由于销售的订阅套餐数量和套餐价格分别出现在不同的表中，我们
需要将这两张表连接起来，以了解销售产生的收入。
138
｜
第
16
章
图
16
-
6
：客户订购频率表
图
16
-
7
：订阅价格表
如前所述，创建这个连接有两个方面的内容：
•
连接条件，决定如何将两张表连接在一起。
•
连接类型，决定了连接参数将返回的内容。 ...
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I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
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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.