Question

在前一篇文章的帮助下，我能够为我想要加入的三个基本表的示例提供以下多表连接解决方案，但是我收到了PRIMARYKEY的参数问题。

select *
FROM       (((
SELECT [PRIMARYKEY] FROM [TABLE 1] 
UNION
SELECT [PRIMARYKEY] FROM [TABLE 2]
UNION
SELECT [PRIMARYKEY] FROM [TABLE 3] )                                                                AS           A
LEFT JOIN  [TABLE 1]      ON    A.[PRIMARYKEY]    =     [TABLE 1].[PRIMARYKEY]               )
LEFT JOIN [TABLE 2]      ON     A.[PRIMARYKEY]     =    [TABLE 2].[PRIMARYKEY]                )
LEFT JOIN [TABLE 3]      ON     A.[PRIMARYKEY]     =    [TABLE 3].[PRIMARYKEY]

我的想法是获得完整的主键列表，然后将其连接到其他表，因为我知道访问中没有完整的连接。

有没有人看到我的脚本有问题？它是“AS A”的一部分，它会把一切都扔掉吗？

Answer 1

请尝试使用别名的内容：

   SELECT *
     FROM ((( SELECT [PRIMARYKEY] AS MyField
                FROM [TABLE 1]
              UNION
              SELECT [PRIMARYKEY] AS MyField
                FROM [TABLE 2]
              UNION
              SELECT [PRIMARYKEY] AS MyField
                FROM [TABLE 3]
            ) AS A
            LEFT JOIN [TABLE 1]
                   ON A.[MyField] = [TABLE 1].[PRIMARYKEY] 
           )
           LEFT JOIN [TABLE 2]
                  ON A.[MyField] = [TABLE 2].[PRIMARYKEY] 
         )  
         LEFT JOIN [TABLE 3]
                ON A.[MyField] = [TABLE 3].[PRIMARYKEY]

你可以在访问中进行笛卡尔连接（这就是我知道完全连接的方式）。我经常使用一个名为dual的行表来总是返回一行......（就像在oracle中一样）。

访问中的多个连接，请求参数值

1 个答案: