August 2022
Beginner to intermediate
463 pages
9h 22m
Chinese
Content preview from Tableau Prep即学即用
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148
｜
第
17
章
17.2
如果数据结构不一样怎么办
由于
Prep Builder
中的联合是基于列名匹配的，当这些名称不一样时，就会在生
成的数据集中出现不匹配。例如，在
Leeds
商店销售表中的
Scent
（气味）列头和
York
商店销售表中的
Type
（类型）列头下获得了相同的数据（见图
17-4
和图
17-
5
）。
图
17
-
4
：包含 Scent（气味）列头的 Leeds 商店销售情况
图
17
-
5
：包含 Type（类型）列头的 York 商店销售情况
因此，在正常的联合中，即使你可能认为列内容应该相互堆叠，但在生成的表中它
们将不匹配（也就是说，同一数据将有两个单独的列）。当发生这种情况时，每个
表中的行都会有空值，在另一个表中没有找到匹配的列（见图
17-6
）。
图
17
-
6
：联合后具有不匹配字段的数据
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