是否有可能优化这个ms sql查询？

Question

此查询很小但是我的Access FrontEnd / SQL BackEnd应用程序停止运行速度变慢。 有没有办法优化它？

据我所知，它显示了最后一个CultureStepID的CID和WeekNr。

SELECT DISTINCT Culture.CID,
(SELECT TOP (1) WeekNr
FROM CultureStep
WHERE (CultureID = Culture.CID)
ORDER BY CultureStepID) AS normalstartweek

FROM Culture
INNER JOIN CultureStep ON Culture.CID= CultureStep.CID

编辑：

查询行数：2309

CultureStep表：13961

文化表：2472

Answer 1

试试这个：

第一种解决方案（您通过CultureStep的存在显示所有文化独立）：

SELECT Culture.CID,
(SELECT CS.WeekNr
FROM CultureStep CS
WHERE (CS.CultureID = Culture.CID)
AND NOT EXISTS(
    SELECT 'NEXT'
    FROM CultureStep CS2
    WHERE CS2.CultureID = CS.CultureID
    AND CS2.CultureStepID > CS.CultureStepID)
) AS normalstartweek
FROM Culture

第二个解决方案:(如果存在链接的CultureStep，则显示所有文化）：

SELECT Culture.CID,
(SELECT CS.WeekNr
FROM CultureStep CS
WHERE (CS.CultureID = Culture.CID)
AND NOT EXISTS(
    SELECT 'NEXT'
    FROM CultureStep CS2
    WHERE CS2.CultureID = CS.CultureID
    AND CS2.CultureStepID > CS.CultureStepID)
) AS normalstartweek
FROM Culture
WHERE EXISTS(
    SELECT 'CultureStep'
    FROM CultureStep
    WHERE (CultureID = Culture.CID)
)

Answer 2

SELECT DISTINCT Culture.CID,
(SELECT TOP (1) WeekNr
FROM CultureStep
WHERE (CultureID = Culture.CID)
ORDER BY CultureStepID) AS normalstartweek
FROM Culture
WHERE Exists(SELECT CID FROM CultureStep WHERE CultureStep.CID=Culture.CID)