August 2022
Beginner to intermediate
463 pages
9h 22m
Chinese
Content preview from Tableau Prep即学即用
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278
｜
第
31
章
REGEXP_MATCH([
String Field
],'regex pattern')
31.3.2 REGEXP_REPLACE()
函数
REGEXP_REPLACE()
函数指定了要替换的字符串字段的一部分以及要替换的值。
REGEXP_REPLACE([
String Field
],'
Substring to replace
','
Replacement value
')
31.4 Regex
（正则表达式）应用案例
正则表达式所提供的灵活性使其可用于大量的场景。本节将介绍一些最常见的情况。
31.4.1
替换常见错误
许多字符串字段来自手工输入的文本。这可能意味着一个数据字段内包含了重复的错
误，在进行准确的分析之前需要将其删除。例如，如果你有已提取出的不同事件的时间，
但格式不同，你需要从字符串中提取相关的值，然后才能开始分析（见图
31-2
）。
图
31
-
2
：基本的时间字段
在这个例子中，需要从这个字符串中提取时间。图
31-3
展示了如何使用
REGEXP_
EXTRACT()
来实现这一目的。
图
31
-
3
：使用 REGEXP_EXTRACT() 函数提取时间
这将返回你需要的结果（见图
31-4
）。
｜
279
使用正则表达式
图
31
-
4
：图
31
-
3
中 REGEXP_EXTRACT() 函数计算的结果 ...
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