Question

我有一个名为authors的主键和一个名为books的字段的数据集。

表格如下所示：

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表（一对多关系），主键（作者）每本书出现不止一次。即

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

我需要在微软访问中使用SQL，我认为它涉及拆分功能，但我对如何执行此查询感到茫然。

非常感谢任何见解！

非常感谢

Answer 1

好吧，既然代码很难实现，而你只有2代码，我想我可以分享一个已实现的解决方案：

（将MyTable替换为您的表名，并使用正确的名称查找并替换所有字段名称：

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(','))), "") <> ""
)

Microsoft Access SQL逗号分隔值

1 个答案: