多UNION查詢不起作用

Question

的多個UNION查詢：

SELECT [Ordine numero] AS ordine, [data ordine] AS data, comm AS commessa 
FROM [archivio globale] 
WHERE [ordine numero] IS NOT NULL 

UNION 

SELECT [numero ordine cliente] AS ordine, [data ordine cliente] AS data, numero AS commessa 
FROM [ricambi] 
WHERE [numero ordine cliente] IS NOT NULL 

UNION 

SELECT [numero ordine cliente] AS ordine, [data ordine cliente] AS data, numero AS commessa 
FROM [trasferte] 
WHERE [numero ordine cliente] IS NOT NULL 

ORDER BY [ordine]; 

它不工作，我得到的錯誤信息：

[mysql][odbc 5.1 Driver][mysqld-5.5.14]You have an error in your SQL syntax ...

雖然單個UNION查詢工作正常（沒有第二次聯合聲明）？該怎麼辦？

Answer 1

您已將您的問題標記爲MySQL，並且您正在使用方括號[]。據我所知，方括號是而不是對MySQL有效，並且只對Microsoft產品（SQL Server/MS Access）有效。因此，如果您需要附上表格/列名稱，請使用反引號`。

From the documentation:

的標識符引號字符是反引號（「`」）：

所以我覺得您的查詢應該是：

SELECT `Ordine numero` AS ordine, `data ordine` AS data, comm AS commessa 
FROM `archivio globale` 
WHERE `ordine numero` IS NOT NULL 

UNION ALL 

SELECT `numero ordine cliente` AS ordine, `data ordine cliente` AS data, numero AS commessa 
FROM `ricambi` 
WHERE `numero ordine cliente` IS NOT NULL 

UNION ALL 

SELECT `numero ordine cliente` AS ordine, `data ordine cliente` AS data, numero AS commessa 
FROM `trasferte` 
WHERE `numero ordine cliente` IS NOT NULL 

ORDER BY `ordine`; 

編輯，如果你是使用MS Access，那麼您將需要使用方括號：

SELECT * 
FROM 
(
    SELECT [Ordine numero] AS ordine, [data ordine] AS data, comm AS commessa 
    FROM [archivio globale] 
    WHERE [ordine numero] IS NOT NULL 

    UNION ALL 

    SELECT [numero ordine cliente] AS ordine, [data ordine cliente] AS data, numero AS commessa 
    FROM [ricambi] 
    WHERE [numero ordine cliente] IS NOT NULL 

    UNION ALL 

    SELECT [numero ordine cliente] AS ordine, [data ordine cliente] AS data, numero AS commessa 
    FROM [trasferte] 
    WHERE [numero ordine cliente] IS NOT NULL 
) x 
ORDER BY [ordine]; 

Answer 2

這是一個MyODBC錯誤，請參閱offical entry here。截至今天，它仍然是開放的...

[編輯]我找到了一個簡單的解決方案：myODBC只會理解查詢與一個UNION（或UNION ALL）。所以你必須用()包裝UNION的右邊部分。另外，你必須先結束每個查詢與;，像這樣：

SELECT [Ordine numero] AS ordine, [data ordine] AS data, comm AS commessa 
FROM [archivio globale] 
WHERE [ordine numero] IS NOT NULL; 

UNION ALL (

SELECT [numero ordine cliente] AS ordine, [data ordine cliente] AS data, numero AS commessa 
FROM [ricambi] 
WHERE [numero ordine cliente] IS NOT NULL; 

UNION ALL 

SELECT [numero ordine cliente] AS ordine, [data ordine cliente] AS data, numero AS commessa 
FROM [trasferte] 
WHERE [numero ordine cliente] IS NOT NULL 
); 

，當然還有，你必須採用同樣的方法來這一部分了。舉例來說，如果你需要一個更UNION ALL在您查詢：

SELECT [Ordine numero] AS ordine, [data ordine] AS data, comm AS commessa 
FROM [archivio globale] 
WHERE [ordine numero] IS NOT NULL; 

UNION ALL (

SELECT [numero ordine cliente] AS ordine, [data ordine cliente] AS data, numero AS commessa 
FROM [ricambi] 
WHERE [numero ordine cliente] IS NOT NULL; 

UNION ALL (

SELECT [numero ordine cliente] AS ordine, [data ordine cliente] AS data, numero AS commessa 
FROM [trasferte] 
WHERE [numero ordine cliente] IS NOT NULL; 

UNION ALL 

SELECT [numero ordine cliente] AS ordine, [data ordine cliente] AS data, numero AS commessa 
FROM [xxx] 
WHERE [numero ordine cliente] IS NOT NULL 
));