模糊的外连接？

Question

我收到以下错误消息...

“无法执行 SQL 语句，因为它包含不明确的外连接。要强制首先执行其中一个连接，请创建一个单独的查询来执行第一个连接，然后将该查询包含在您的 SQL 语句中。”

我怎样才能解决这个问题？？？如果我将“LEFT JOIN”替换为“INNER JOIN”，则错误消失，但未完成所需的操作。

这是我的代码：

SELECT route.productfam, 
       facility.location, 
       asmlines.line, 
       tableconsolidate2.sumofyr, 
       tableconsolidate2.sumofyr0, 
       tableconsolidate2.sumofyr1, 
       tableconsolidate2.sumofyr2, 
       tableconsolidate2.sumofyr3, 
       tableconsolidate2.sumofyr4, 
       tableconsolidate2.sumofyr5, 
       route.cycletime, 
       route.numperprod, 
       facilitylines.operationalhr, 
       [18months].[month 1], 
       [18months].[month 2], 
       [18months].[month 3], 
       [18months].[month 4], 
       [18months].[month 5], 
       [18months].[month 6], 
       [18months].[month 7], 
       [18months].[month 8], 
       [18months].[month 9], 
       [18months].[month 10], 
       [18months].[month 11], 
       [18months].[month 12], 
       [18months].[month 13], 
       [18months].[month 14], 
       [18months].[month 15], 
       [18months].[month 16], 
       [18months].[month 17], 
       [18months].[month 18] 
FROM   ((productfamily 
         INNER JOIN (facility 
                     INNER JOIN tableconsolidate2 
                             ON facility.location = 
                                tableconsolidate2.[build plant]) 
                 ON productfamily.productfamily = 
                    tableconsolidate2.[prod series]) 
        LEFT JOIN 18months 
               ON ( facility.location = [18months].location ) 
                  AND ( productfamily.productfamily = [18months].[item type] )) 
       INNER JOIN ((asmlines 
                    INNER JOIN facilitylines 
                            ON asmlines.line = facilitylines.line) 
                   INNER JOIN route 
                           ON asmlines.line = route.line) 
               ON ( productfamily.productfamily = route.productfam ) 
                  AND ( facility.location = facilitylines.facility ) 

GROUP BY route.productfam, facility.location, Asmlines.line, tableconsolidate2.SumOfyr, tableconsolidate2.SumOfyr0, tableconsolidate2.SumOfyr1, tableconsolidate2.SumOfyr2, tableconsolidate2.SumOfyr3, tableconsolidate2.SumOfyr4, tableconsolidate2.SumOfyr5, route.cycletime, route.numperprod, facilitylines.operationalhr, [18Months].[Month 1], [18Months].[Month 2], [18Months].[Month 3], [18Months].[Month 4], [18Months].[Month 5], [18Months].[Month 6], [18Months].[Month 7], [18Months].[Month 8], [18Months].[Month 9], [18Months].[Month 10], [18Months].[Month 11], [18Months].[Month 12], [18Months].[Month 13], [18Months].[Month 14], [18Months].[Month 15], [18Months].[Month 16], [18Months].[Month 17], [18Months].[Month 18], route.productfam

ORDER BY facility.location;

Answer 1

如果您创建的查询包含 LEFT JOIN 和 INNER JOIN，Access 可能无法确定首先执行哪个连接操作。由于先执行左连接还是先执行内连接，结果会有所不同，因此 Access 会显示错误消息：

要更正此错误，您必须修改查询以明确首先执行哪个连接。

因此，可以通过将其拆分为两个查询，然后将它们加入和附加查询来实现解决方案。

查询 1：

SELECT route.productfam, facility.location, Asmlines.line, [18Months].[Month 1], [18Months].[Month 2], [18Months].[Month 3], [18Months].[Month 4], [18Months].[Month 5], [18Months].[Month 6], [18Months].[Month 7], [18Months].[Month 8], [18Months].[Month 9], [18Months].[Month 10], [18Months].[Month 11], [18Months].[Month 12], [18Months].[Month 13], [18Months].[Month 14], [18Months].[Month 15], [18Months].[Month 16], [18Months].[Month 17], [18Months].[Month 18], route.cycletime, route.numperprod, facilitylines.operationalhr
FROM (facility INNER JOIN (ProductFamily INNER JOIN 18Months ON ProductFamily.productfamily = [18Months].[Item Type]) ON facility.location = [18Months].Location) INNER JOIN ((Asmlines INNER JOIN facilitylines ON Asmlines.line = facilitylines.line) INNER JOIN route ON Asmlines.line = route.line) ON (ProductFamily.productfamily = route.productfam) AND (facility.location = facilitylines.facility)
GROUP BY route.productfam, facility.location, Asmlines.line, [18Months].[Month 1], [18Months].[Month 2], [18Months].[Month 3], [18Months].[Month 4], [18Months].[Month 5], [18Months].[Month 6], [18Months].[Month 7], [18Months].[Month 8], [18Months].[Month 9], [18Months].[Month 10], [18Months].[Month 11], [18Months].[Month 12], [18Months].[Month 13], [18Months].[Month 14], [18Months].[Month 15], [18Months].[Month 16], [18Months].[Month 17], [18Months].[Month 18], route.cycletime, route.numperprod, facilitylines.operationalhr, route.productfam
ORDER BY facility.location;

查询 2：

SELECT route.productfam, facility.location, Asmlines.line, tableconsolidate2.SumOfyr, tableconsolidate2.SumOfyr0, tableconsolidate2.SumOfyr1, tableconsolidate2.SumOfyr2, tableconsolidate2.SumOfyr3, tableconsolidate2.SumOfyr4, tableconsolidate2.SumOfyr5, route.cycletime, route.numperprod, facilitylines.operationalhr
FROM (ProductFamily INNER JOIN (facility INNER JOIN tableconsolidate2 ON facility.location = tableconsolidate2.[Build Plant]) ON ProductFamily.productfamily = tableconsolidate2.[Prod Series]) INNER JOIN ((Asmlines INNER JOIN facilitylines ON Asmlines.line = facilitylines.line) INNER JOIN route ON Asmlines.line = route.line) ON (ProductFamily.productfamily = route.productfam) AND (facility.location = facilitylines.facility)
GROUP BY route.productfam, facility.location, Asmlines.line, tableconsolidate2.SumOfyr, tableconsolidate2.SumOfyr0, tableconsolidate2.SumOfyr1, tableconsolidate2.SumOfyr2, tableconsolidate2.SumOfyr3, tableconsolidate2.SumOfyr4, tableconsolidate2.SumOfyr5, route.cycletime, route.numperprod, facilitylines.operationalhr, route.productfam
ORDER BY facility.location;

查询 3：

Query 1 LEFT JOIN Query 2