Question

我有一系列三个表，我想在Excel VBA应用程序中使用ADODB将它们连接在一起。我正在使用以下查询，这会导致“不支持JOIN表达式”错误：

SELECT    tb1.date, 
          tb1.longID, 
          tb1.fld1,
          tb2.fld2,
          tb3.shortID,
          SUM(tb1.fld3) AS three, 
          SUM(tb1.fld4) AS four, 
          SUM(tb3.fld5) AS five
FROM      ([Table1$] AS tb1 LEFT JOIN [Table2$] AS tb2 ON tb1.longID = tb2.longID)
LEFT JOIN [Table3$]  AS tb3
ON        (tb3.shortID = tb2.shortID AND tb1.date = tb3.date)
GROUP BY  tb1.date, tb1.longID, tb3.shortID, tb2.fld3, tb1.fld2

如果我忽略shortID列对，则查询工作正常。如果我省略date列对，则查询工作正常。但是，当我将两者结合起来时，就遇到了问题。

任何帮助将不胜感激！

谢谢。

Answer 1

尝试让查询的ON部分中的所有内容都放在括号中。

JOIN操作中的ON语句不完整或包含太多表。您可能需要将ON表达式放在WHERE子句中。

SELECT    tb1.date, 
          tb1.longID, 
          tb1.fld1,
          tb2.fld2,
          tb3.shortID,
          SUM(tb1.fld3) AS three, 
          SUM(tb1.fld4) AS four, 
          SUM(tb3.fld5) AS five
FROM      
[Table1$] AS tb1 
LEFT JOIN [Table2$] AS tb2 ON (tb1.longID = tb2.longID)
LEFT JOIN [Table3$]  AS tb3 ON (tb3.shortID = tb2.shortID)
WHERE tb1.date = tb3.date
GROUP BY  tb1.date, tb1.longID, tb3.shortID, tb2.fld3, tb1.fld2

Answer 2

在线条款的目的是联接 2 表，但是您尝试使用ON (tb3.shortID = tb2.shortID AND tb1.date = tb3.date)同时联接 3 表。您可以通过两种方式解决此问题：

将ON的一部分移至WHERE子句，以便仅涉及2个表。

...
FROM      ([Table1$] AS tb1
           LEFT JOIN [Table2$] AS tb2
               ON tb1.longID = tb2.longID)
          LEFT JOIN [Table3$] AS tb3
              ON tb2.shortID = tb3.shortID
WHERE tb1.date = tb3.date
...

使用子查询

SELECT
    x.date, 
    x.longID, 
    x.fld1,
    x.fld2,
    tb3.shortID,
    SUM(x.fld3) AS three, 
    SUM(x.fld4) AS four, 
    SUM(tb3.fld5) AS five
FROM      
    (SELECT
         tb1.date, tb1.longID, tb1.fld1,
         tb2.fld2
     FROM
         [Table1$] AS tb1 
         LEFT JOIN [Table2$] AS tb2
             ON tb1.longID = tb2.longID
    ) x
    LEFT JOIN [Table3$]  AS tb3
        ON (x.shortID = tb3.shortID AND x.date = tb3.date)
GROUP BY
    x.date, x.longID, x.fld1, x.fld2, tb3.shortID

Excel VBA（ADODB）中的嵌套联接结果“不支持JOIN表达式”

2 个答案: