August 2022
Beginner to intermediate
463 pages
9h 22m
Chinese
Content preview from Tableau Prep即学即用
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｜
69
处理日期问题
•
季度。
•
月份。
•
星期。
•
日。
•
年中的某日。
•
工作日。
•
财政年度。
•
财政季度。
•
财政月。
•
公共假期。
•
周末。
这一点很重要，因为在使用未内置日期解析功能的工具时，必须加入所有相关的列
来挑选出你分析所需的日期部分（更不用说数据库管理员要保持表格的更新了）。
Tableau
的所有产品都非常灵活地使用了日期字段，以快速获取想要分析的数据部分，
无论是一年的周数还是工作日的信息。这意味着不需要将所有的日期部分单独存储
为单独的列。如果将日期组织成单列，那么在
Desktop
中的分析就会容易得多，因
为无论想使用哪种日期部分，都是将同一个字段添加到视图中。这样就可以灵活地
通过不同的日期部分解析方法来分析数据，而不必在分析中不断地交换数据字段。
8.4
新纪元日期
UNIX epoch dates
（新纪元日期）是一种常见于数据集的日期格式，但对普通人来
说，乍一看会觉得摸不着头脑。由于整数（整个数字）比长字符串更容易在数据库
中存储，新纪元日期反映了自
1970
年
1
月
1
日
00:00:00
（
UTC/GMT
）以来已经过
去的秒数，不计算闰秒。例如，我们的示例日期
25/09/2019
的午夜将对应于一个值
为
1569369600
的数。
许多数据准备从业人员面临的困难是，如何将这种格式转换为现代
BI
工具中可使用
的形式。在
Tableau
中，你可以使用
dateadd()
函数（见图
8-2
）比较容易地将这个
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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.