Question

我正在尝试在Access 2003中编写一个基于现有表创建新表的查询。我正在使用Make Table Query。

在：

NAME  A_1   A_2  B_1    B_2
X      1    2    3      4
Y      5    6    7      8

在

NAME    Section Value1  Value2  
X          A    1        2  
X          B    3        4  
Y          A    5        6  
Y          B    7        8

Answer 1

创建SELECT查询，从现有表格的每一行检索 A_1 和 A_2 值：

SELECT e1.NAME, 'A' AS [Section], e1.A_1 AS Value1, e1.A_2 AS Value2
FROM tblExisting AS e1

然后创建一个类似的查询，检索 B_1 和 B_2 值，并UNION两个SELECT语句：

SELECT e1.NAME, 'A' AS [Section], e1.A_1 AS Value1, e1.A_2 AS Value2
FROM tblExisting AS e1
UNION ALL
SELECT e2.NAME, 'B' AS [Section], e2.B_1 AS Value1, e2.B_2 AS Value2
FROM tblExisting AS e2

从那里，您可以基于UNION查询构建一个make table查询：

SELECT sub.*
    INTO tblNew
FROM
    (
        SELECT e1.NAME, 'A' AS [Section], e1.A_1 AS Value1, e1.A_2 AS Value2
        FROM tblExisting AS e1
        UNION ALL
        SELECT e2.NAME, 'B' AS [Section], e2.B_1 AS Value1, e2.B_2 AS Value2
        FROM tblExisting AS e2
    ) AS sub;

基于现有表创建新表

1 个答案: