Microsoft Access SQL 逗号分隔值

Question

我有一个数据集，其中包含一个名为作者的主键和一个名为书籍的字段。

table 看起来像这样：

Authors (primary key)     Books
John                      Fathom,Mouseover,Keycard
Kyle                      Teachers,Carl,Phone

我知道这违反了 1NF，我正在尝试创建一个新的 table（一对多关系），每本书的主键（作者）出现不止一次。即

Authors                   Books
John                      Fathom
John                      Mouseover
John                      Keycard
Kyle                      Teachers
Kyle                      Carl
Kyle                      Phone

我需要在microsoft access中使用SQL，我认为它涉及到拆分功能，但我不知道如何执行此查询。

任何见解将不胜感激！

非常感谢

Answer 1

嗯，由于代码比较难实现，而你只有2个，我想我可以分享一个实现的解决方案：

（将 MyTable 替换为您的表名，然后将所有字段名称查找并替换为正确的名称）：

SELECT * Into NewTable FROM (
SELECT Author, IIf(InStr(1, [Books], ',') = -1, [Books], Left([Books], InStr(1, [Books], ',') - 1)) As Book
FROM MyTable
WHERE IIf(InStr(1, [Books], ',') = -1, [Books], Left([Books], InStr(1, [Books], ',') - 1)) <> ""
UNION ALL
SELECT Author, IIf( InStr(1,[Books],',')> 0, IIf(InStr(InStr(1,[Books],',') + Len(','), [Books] , ',') < 1, Mid([Books], InStr(1,[Books],',') + Len(',')), Mid([Books], InStr(1,[Books],',') + Len(','), InStr(InStr(1,[Books],',') + Len(','), [Books] , ',') - InStr(1,[Books],',') - Len(','))), "")  As Book
FROM MyTable
WHERE IIf( InStr(1,[Books],',')> 0, IIf(InStr(InStr(1,[Books],',') + Len(','), [Books] , ',') < 1, Mid([Books], InStr(1,[Books],',') + Len(',')), Mid([Books], InStr(1,[Books],',') + Len(','), InStr(InStr(1,[Books],',') + Len(','), [Books] , ',') - InStr(1,[Books],',') - Len(','))), "")  <> ""
UNION ALL
SELECT Author, IIf( InStr(InStr(1,[Books],',') + Len(','), [Books],',')> 0, IIf(InStr(InStr(InStr(1,[Books],',') + Len(','), [Books],',') + Len(','), [Books] , ',') < 1, Mid([Books], InStr(InStr(1,[Books],',') + Len(','), [Books],',') + Len(',')), Mid([Books], InStr(InStr(1,[Books],',') + Len(','), [Books],',') + Len(','), InStr(InStr(InStr(1,[Books],',') + Len(','), [Books],',') + Len(','), [Books] , ',') - InStr(InStr(1,[Books],',') + Len(','), [Books],',') - Len(','))), "")  As Book
FROM MyTable
WHERE IIf( InStr(InStr(1,[Books],',') + Len(','), [Books],',')> 0, IIf(InStr(InStr(InStr(1,[Books],',') + Len(','), [Books],',') + Len(','), [Books] , ',') < 1, Mid([Books], InStr(InStr(1,[Books],',') + Len(','), [Books],',') + Len(',')), Mid([Books], InStr(InStr(1,[Books],',') + Len(','), [Books],',') + Len(','), InStr(InStr(InStr(1,[Books],',') + Len(','), [Books],',') + Len(','), [Books] , ',') - InStr(InStr(1,[Books],',') + Len(','), [Books],',') - Len(','))), "") <> ""
)

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