August 2022
Beginner to intermediate
463 pages
9h 22m
Chinese
Content preview from Tableau Prep即学即用
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408
｜
第
46
章
46.4
在
Prep Builder
中创建标识符数据字段
前述所有要点都依赖于数据源中可用的
ID
（标识符）或
Key
（键）。但是，如果
准备将数据源存储在数据库中，则需要从所拥有的数据中创建一个键。让我们使用
Superstore
（超市），即作为
Tableau Prep Builder
或
Tableau Desktop
软件包的一部
分下载的示例数据集，并创建一个可以作为参考表的类别表。
从
Prep Builder 2020.1
版本开始，该工具包含了自动创建排名字段的功能。在如图
46-6
所示的示例中，可以通过基于
Category
（类别）数据字段创建排名以在一定程
度上降低复杂性。
图
46
-
6
：通过概况窗格数据字段菜单创建排名
选择该选项将启动排名可视化编辑器，这使得该过程无须编码即可实现（见图
46-7
）。
｜
409
在数据中使用标识符和键
图
46
-
7
：在 Visual Editor（可视化编辑器）中设置排名
在默认的排名设置中，排名的值是按照归属到每个类别的行数来排序的。要想更
进一步，并为类别创建一个简单的
ID
，需将
Order by
（排序）中的
rank
选项改为
Dense Rank
（密集排名
/
并列排名，即相同值排名相同且排名连续不间断，如图
46-8
所示）。
图
46
-
8
：在 Visual Editor ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
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.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
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.