將SQL查詢轉換爲Access查詢 - SELECT內的SELECT

Question

我在SQL Server中有一個查詢，我試圖將其轉換爲MS-Access 2003中的查詢。該查詢旨在用作報表的基礎。該報告有兩個字段：'已分配案例'和'已關閉案例'。

SELECT 
(SELECT COUNT(*) 
FROM CaseDetail 
WHERE CaseAssignedDate Between '1/1/2008' AND '1/1/2009') as 'Cases Assigned', 
(SELECT COUNT(*) 
FROM CaseDetail 
WHERE CaseClosedDate BETWEEN '1/1/2008' AND '1/1/2009') as 'Cases Closed' 

我使用的是SQL Access 2003中有困難，我已經取代了'字符#用於訪問的緣故，但仍然沒有喜悅。 Access在SELECT語句中有SELECT問題嗎？我從Access獲得的錯誤不太有用。

Reserved error (-3205); there is no message for this error 

另外，如果SQL語句是如此需要從多個表中獲取數據，那該怎麼辦？例如...

SELECT 
(SELECT COUNT(*) 
FROM AssignedCases 
WHERE CaseAssignedDate Between '1/1/2008' AND '1/1/2009') as 'Cases Assigned', 
(SELECT COUNT(*) 
FROM ClosedCases 
WHERE CaseClosedDate BETWEEN '1/1/2008' AND '1/1/2009') as 'Cases Closed' 

這適用於沒有問題的SQL，但不適用於Access。

Answer 1

允許在Access和SQL服務器中嵌套查詢，但至少在SQL服務器中它要求您爲嵌套查詢設置一個假別名，並且嵌套查詢中的所有列都需要一個名稱。這可能導致了錯誤。

我建議以下查詢：

SELECT q1.CasesAssigned, q2.CasesClosed 
FROM 
(SELECT COUNT(*) AS CasesAssigned 
FROM CaseDetail 
WHERE CaseAssignedDate Between '1/1/2008' AND '1/1/2009') as q1, 
(SELECT COUNT(*) AS CasesClosed 
FROM CaseDetail 
WHERE CaseClosedDate BETWEEN '1/1/2008' AND '1/1/2009') as q2 

Answer 2

3205錯誤是交叉表列標題太多。

這是否查詢爲您解決：

SELECT 'Cases Asssigned' as Type, COUNT(*) 
FROM CaseDetail 
WHERE CaseAssignedDate Between '1/1/2008' AND '1/1/2009' 
UNION 
SELECT 'Cases Closed'as Type, COUNT(*) 
FROM CaseDetail 
WHERE CaseClosedDate BETWEEN '1/1/2008' AND '1/1/2009') 

結果將在兩行而不是一個。

Answer 3

我目前還沒有Windows機器測試，但類似這樣的應該工作。

SELECT SUM(IIF(CaseAssignedDate 
      BETWEEN #1/1/2008# AND #1/1/2009#, 1, 0)) AS CasesAssigned, 
     SUM(IIF(CaseClosedDate 
      BETWEEN #1/1/2008# AND #1/1/2009#, 1, 0)) AS CasesClosed 
    FROM CaseDetail 

在我的經驗，一般最好在可能情況下，避免在Access中使用子查詢。

---

編輯：
迴應您的意見，我只測試了Access允許這種替代方法：

SELECT * 
    FROM 
(
SELECT 'CasesAssigned', COUNT(*) AS Total 
    FROM AssignedCases 
WHERE CaseAssignedDate BETWEEN #1/1/2008# AND #1/1/2009# 

UNION ALL 

SELECT 'ClosedCases', COUNT(*) AS Total 
    FROM ClosedCases 
WHERE CaseClosedDate BETWEEN #1/1/2008# AND #1/1/2009# 
); 

---

EDIT2：
littlegreen's answer會工作，如果你需要一個一個排結果集。

Answer 4

我不知道你在哪裏得到這個錯誤信息，但你的問題是試圖沒有至少一個表或查詢執行Select語句。你需要一些「虛擬」表，只有一個記錄來完成這一點。

SELECT 
    (SELECT COUNT(*) 
    FROM CaseDetail 
    WHERE CaseAssignedDate Between '1/1/2008' AND '1/1/2009' 
    ) as 'Cases Assigned', 
    (SELECT COUNT(*) 
    FROM CaseDetail 
    WHERE CaseClosedDate BETWEEN '1/1/2008' AND '1/1/2009' 
    ) as 'Cases Closed' 
FROM DummyTableWithOneRecord; 

Answer 5

既然你有在SQL Server可以查詢，創建一個使用該查詢（在SQL Server），並返回結果集接入接入傳遞查詢。

或者，根據該SELECT語句創建一個SQL Server視圖並鏈接到來自Access的視圖。

由於它已經在SQL Server中工作，我沒有看到在Access中重新創建查詢的任何附加值。