Question

我正在尝试使用以下代码：

m_Set.ClearQueryInfo();
m_Set.SetParameterWhere("PatID = @PatIDParam AND EffectiveEnrollmentDate IN (Select MAX(EffectiveEnrollmentDate))");
m_Set.SetWhere("PatID = ? AND EffectiveEnrollmentDate IN (Select MAX(EffectiveEnrollmentDate))");
m_Set.SetNumParams(1);
m_Set.SetParam("@PatIDParam", 1, PatIDParam.ToString());

但我最终收到以下错误：

聚合可能不会出现在 WHERE子句，除非它在一个 HAVING子句中包含的子查询或选择列表，列为聚合是外部参考， SELECT dbo。[PatRoster]。* FROM dbo。[PatRoster]在哪里PatID = @PatIDParam AND EffectiveEnrollmentDate IN（选择 MAX（EffectiveEnrollmentDate））的

Answer 1

您没有指定要从此处查询的表源：

(Select MAX(EffectiveEnrollmentDate))

将其更改为：

(Select MAX(EffectiveEnrollmentDate) FROM PatRoster)

Answer 2

您的查询无效 - Select MAX(EffectiveEnrollmentDate)未完成;它必须从该子查询中的某个地方选择EffectiveEnrollmentDate。

此外，MAX()只返回一个值，因此不需要IN - 您可以直接进行比较运算符=。

Answer 3

正如错误消息所示，正确的方法是使用子查询：

select bar.foo
from bar
where bar.foo = (select max(subbar.foo) from bar as subbar); -- subquery

Answer 4

子查询：(Select MAX(EffectiveEnrollmentDate))缺少一个源，它不能引用外部查询

SELECT dbo.[PatRoster].* 
FROM dbo.[PatRoster] 
WHERE PatID = @PatIDParam AND EffectiveEnrollmentDate = (Select MAX(EffectiveEnrollmentDate) FROM dbo.[PatRoster])

Answer 5

子查询中的聚合不能超过外部查询的值：

AND EffectiveEnrollmentDate IN (Select MAX(EffectiveEnrollmentDate))

你想要做的是：

SELECT dbo.[PatRoster].*
  FROM dbo.[PatRoster]
 WHERE PatID = @PatIDParam
   AND EffectiveEnrollmentDate = (Select MAX(EffectiveEnrollmentDate)
                                    FROM dbo.[PatRoster]
                                   WHERE PatID = @PatIDParam)

除非在子查询中，否则聚合可能不会出现在WHERE子句中

5 个答案: