Question

我正在尝试使用C＃中的SQLce（版本3.5）数据库中的生效日期进行过滤。这是我的查询：

SELECT        FirstName, LastName, HomeID, ConditionID, ADate, OwnerID
FROM            Sys_HomeOwner
WHERE        (ADate =
                             (SELECT        MAX(ADate) AS Expr1
                               FROM            Sys_HomeOwner AS Sys_HomeOwner_1))

返回的错误是：

解析查询时出错。（标记行号= 1，标记行 offset = 118，令牌错误=选择]

我一直在做一些查询，似乎可以在SQLCE中进行子选择。如果我拉出子选择，那么无论如何拉动最大日期，它对于整个表运行正常。

我做错了什么？

感谢您的帮助。

Answer 1

你提到每行最多，我认为你需要使用GROUP BY。

怎么样：

SELECT FirstName, LastName, NameID, ConditionID, ADate, OwnerID
FROM Sys_HomeOwner h
LEFT OUTER JOIN (SELECT MAX(ADate) AS maxdate, HomeID
                 FROM Sys_HomeOwner
                 GROUP BY HomeID) AS effectiveDates
     ON h.HomeID = effectiveDates.HomeID
WHERE h.ADate = effectiveDates.maxdate

假设您想获取每个HomeID的最新日期

Answer 2

SELECT TOP 1 FirstName, LastName, HomeID, ConditionID, ADate, OwnerID 
FROM Sys_HomeOwner 
ORDER BY ADate DESC

SQL CE使用SubSelect按生效日期过滤

2 个答案: