sql - 访问中的联合查询太复杂而无法评估

Question

我在访问时遇到以下错误，我不知道为什么。我将从荷兰语翻译它:

"Deze expressie is niet correct getypt of te complex voor evaluatie.
Een numerieke expressie kan bijvoorbeeld te veel gecompliceerde elementen bevatten.
Probeer de expressie te vereenvoudigen door verschillende delen van de expressie toe te wijzen aan variabelen."

英语:

"This expression has a spelling error or is too complex for evaluation.
A numeric expression could contain to many complex elements.
Try to simplify the expression by assigning several parts to variables."

奇怪的是我的查询是单独工作的。该错误仅在我使用 UNION 函数时发生。因为他们分开工作，我不认为这是一个打字错误？树查询是另一种生成树的查询。 (3 个表与 id 和 arent id 链接)

所有其他表都只是数据。

SELECT "(z) Opleidingen" AS Campaign, LCase([Tree query]![sector] & "#" & IIf([Tree query]![cluster] Is Null, [Tree query]![subsector],[Tree query]![cluster])& "$" & [Opleidingsnaam]![Collinaam]) AS Adgroup, "Broad" AS [Keyword Type], "0,60" AS [Max CPC], [Opleidingsnaam]![URL] AS [Destination URL], "+" & Replace([Opleidingsnaam]![Opleidingsnaam]," "," +") & " +" & Replace([Locatie]![Keyword]," "," +") AS Keyword, "Active" AS [Keyword Status], Opleidingsnaam.Timestamp AS t1, Locatie.Timestamp AS t2, Null AS t3, Null AS t4, Null AS t5
FROM Locatie, Opleidingsnaam INNER JOIN [Tree query] ON Opleidingsnaam.SectorId = [Tree query].ID
WHERE (((Opleidingsnaam.Timestamp)>[inputdate]) AND ((Opleidingsnaam.Startdatum)>[inputdate])) OR (((Locatie.Timestamp)>[inputdate]) AND ((Opleidingsnaam.Startdatum)>[inputdate])) OR (((Null)>[inputdate]) AND ((Opleidingsnaam.Startdatum)>[inputdate])) OR (((Null)>[inputdate]) AND ((Opleidingsnaam.Startdatum)>[inputdate])) OR (((Null)>[inputdate]) AND ((Opleidingsnaam.Startdatum)>[inputdate]));


UNION


SELECT "(z) Opleidingen" AS Campaign, LCase([Tree query]![sector] & "#" & IIf([Tree query]![cluster] Is Null,[Tree query]![subsector],[Tree query]![cluster])& "$" & [Opleidingsnaam]![Collinaam]) AS Adgroup, "Broad" AS [Keyword Type], "0,60" AS [Max CPC], [Opleidingsnaam]![URL] AS [Destination URL], "+" & Replace([Opleidingsnaam]![Opleidingsnaam]," "," +") & " +" & Replace([Campus]![Keyword]," "," +") AS Keyword, "Active" AS [Keyword Status], Opleidingsnaam.Timestamp AS t1, Campus.Timestamp AS t2, Null AS t3, Null AS t4, Null AS t5
FROM Campus, Opleidingsnaam INNER JOIN [Tree query] ON Opleidingsnaam.SectorId = [Tree query].ID
WHERE (((Opleidingsnaam.Timestamp)>[inputdate]) AND ((Opleidingsnaam.Startdatum)>[inputdate])) OR (((Campus.Timestamp)>[inputdate]) AND ((Opleidingsnaam.Startdatum)>[inputdate])) OR (((Opleidingsnaam.Startdatum)>[inputdate])) OR (((Null)>[inputdate]) AND ((Opleidingsnaam.Startdatum)>[inputdate])) OR (((Null)>[inputdate]) AND ((Opleidingsnaam.Startdatum)>[inputdate]));

有人可以帮我解决这个问题吗？这让我发疯:)

背景:我正在使用联合查询来组合多个查询。查询结合了包含关键字的不同表。我想创建所有可能的关键字组合。这是我在 Google Adwords 中使用的。

提前致谢!

Answer 1

UNION 查询不容易排除故障。我认为@GarethD 是对的——为了给你最好的机会，你应该:

1. 保存每个查询(仔细检查每个查询是否具有相同数量的字段)
2. 将您的 UNION 查询更改为 SELECT * FROM Query1 UNION SELECT * FROM Query2...

如果没有连接，您使用的是笛卡尔积，它会占用大量内存。我怀疑即使这样也无法解决您的问题。如果这不起作用，您可能需要使用一个丑陋的 hack - 遍历所有查询并将结果附加到临时表。