Question

我正在尝试执行以下查询，但收到运行时错误，说明：

"The column is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause."

以下第二行是因上述错误而失败的第二行。我不明白为什么这个查询没有执行，因为第二行不需要分组，因为输出只是count（*），任何关于我需要改变以使其工作的线索？

SELECT @lessonPlans = COUNT(*)
, @lessonPlanResources = (SELECT COUNT(*) FROM dbo.LessonPlanResource lpr where lpr.LessonPlanId = a.LessonPlanId )
FROM
( 
    SELECT DISTINCT lpt.LessonPlanId
    FROM dbo.LearningTargetBreakout ltb
    JOIN dbo.LessonPlanLearningTarget lpt 
        on lpt.LearningTargetId = ltb.LearningTargetId
    WHERE (CASE 
            WHEN ltb.LearningTargetId = @learningTargetId and @learningTargetId is not null THEN 1
            WHEN ltb.CategoryId = @categoryId and @categoryId is not null THEN 1
            WHEN ltb.Grade = @grade and @grade is not null THEN 1
            WHEN ltb.SubjectId = @subjectId and @subjectId is not null THEN 1
            ELSE 0 END) = 1
) a

[编辑]

使用Zeb解决方案的略微变化 - 这是我最终使用的修订代码，它产生了一行聚合，这就是我所追求的。

SELECT @lessonPlans = ISNULL(COUNT(*), 0)
        , @lessonPlanResources = ISNULL(SUM(a.ResCount), 0)
FROM
( 
    SELECT DISTINCT lpt.LessonPlanId, lpr.ResCount
    FROM dbo.LearningTargetBreakout ltb
    JOIN dbo.LessonPlanLearningTarget lpt 
        on lpt.LearningTargetId = ltb.LearningTargetId
    JOIN (SELECT LessonPlanId, COUNT(*) ResCount FROM dbo.LessonPlanResource lpr GROUP BY LessonPlanId) lpr
        ON lpr.LessonPlanId = lpt.LessonPlanId          
    WHERE (CASE 
            WHEN ltb.LearningTargetId = @learningTargetId and @learningTargetId is not null THEN 1
            WHEN ltb.CategoryId = @categoryId and @categoryId is not null THEN 1
            WHEN ltb.GradeId = @grade and @grade is not null THEN 1
            WHEN ltb.SubjectId = @subjectId and @subjectId is not null THEN 1
            ELSE 0 END) = 1
) a

Answer 1

我的猜测是@lessonPlanResources链接到LessonPlanId，而不是聚合。

我的解决方案是加入该子表，并将返回的列设为COUNT。

SELECT @lessonPlans = COUNT(*)
, @lessonPlanResources = SUM(zlpr.reses)
FROM
( 
    SELECT DISTINCT lpt.LessonPlanId, zlpr.reses
    FROM dbo.LearningTargetBreakout ltb
    JOIN dbo.LessonPlanLearningTarget lpt 
        on lpt.LearningTargetId = ltb.LearningTargetId
    JOIN (SELECT LessonPlanId, COUNT(*) reses FROM dbo.LessonPlanResource lpr) zlpr
        ON zlpr.LessonPlanId = lpt.LessonPlanId
    WHERE (CASE 
            WHEN ltb.LearningTargetId = @learningTargetId and @learningTargetId is not null THEN 1
            WHEN ltb.CategoryId = @categoryId and @categoryId is not null THEN 1
            WHEN ltb.Grade = @grade and @grade is not null THEN 1
            WHEN ltb.SubjectId = @subjectId and @subjectId is not null THEN 1
            ELSE 0 END) = 1
) a

Answer 2

您的count(*)是一个聚合函数，而@lessonPlanResources的表达式不是（即使它是COUNT(*)的查询）。因此，表达式必须包含在GROUP BY子句中。

您可以使用公用表表达式（CTE），这也有助于提高可读性。

WITH LPR_CTE as
    (
    SELECT LessonPlanId, COUNT(*) as LessonPlanResourcesCount
    FROM dbo.LessonPlanResource
    GROUP BY LessonPlanId
    ),

    LP_CTE(
    SELECT lpt.LessonPlanId, COUNT(*) as LessonPlansCount
    FROM dbo.LearningTargetBreakout ltb
    JOIN dbo.LessonPlanLearningTarget lpt 
        on lpt.LearningTargetId = ltb.LearningTargetId
    WHERE (CASE 
            WHEN ltb.LearningTargetId = @learningTargetId and @learningTargetId is not null THEN 1
            WHEN ltb.CategoryId = @categoryId and @categoryId is not null THEN 1
            WHEN ltb.Grade = @grade and @grade is not null THEN 1
            WHEN ltb.SubjectId = @subjectId and @subjectId is not null THEN 1
            ELSE 0 END) = 1
    )

SELECT @lessonPlans = LP_CTE.LessonPlansCount
     , @lessonPlanResources = LPR_CTE.LessonPlanResourcesCount
FROM LP_CTE
JOIN LPR_CTE on LP_CTE.LessonPlanId = LPR_CTE.LessonPlanId

Answer 3

您需要GROUP BY a.LessonPlanId并可能将第一个COUNT(*)更改为COUNT(*) OVER()，具体取决于您的具体操作。

但是，这可能会给出多行结果，然后您尝试将这些结果分配给一组标量变量。您尝试做什么？

Answer 4

问题是您正在使用此子查询的分组函数（count）：SELECT COUNT（*）FROM dbo.LessonPlanResource lpr其中lpr.LessonPlanId = a.LessonPlanId

但是，对a.LessonPlanId的引用是一个非分组字段。对您的查询进行分组，您可以引用该字段。

试试这个：

SELECT @lessonPlans = COUNT(*)
, @lessonPlanResources = (SELECT COUNT(*) FROM dbo.LessonPlanResource lpr where lpr.LessonPlanId = a.LessonPlanId )
FROM
( 
    SELECT DISTINCT lpt.LessonPlanId
    FROM dbo.LearningTargetBreakout ltb
    JOIN dbo.LessonPlanLearningTarget lpt 
        on lpt.LearningTargetId = ltb.LearningTargetId
    WHERE (CASE 
            WHEN ltb.LearningTargetId = @learningTargetId and @learningTargetId is not null THEN 1
            WHEN ltb.CategoryId = @categoryId and @categoryId is not null THEN 1
            WHEN ltb.Grade = @grade and @grade is not null THEN 1
            WHEN ltb.SubjectId = @subjectId and @subjectId is not null THEN 1
            ELSE 0 END) = 1
) a
GROUP BY a.LessonPlanID

Answer 5

从外部选择中删除COUNT。
在内部选择中使用COUNT DISTINCT

SELECT 
   @lessonPlans = a.B,
   @lessonPlanResources = (SELECT COUNT(*) FROM dbo.LessonPlanResource lpr where lpr.LessonPlanId = a.LessonPlanId )
FROM
( 
    SELECT COUNT (DISTINCT, lpt.LessonPlanId) AS B
    FROM dbo.LearningTargetBreakout ltb
    JOIN dbo.LessonPlanLearningTarget lpt 
        on lpt.LearningTargetId = ltb.LearningTargetId
    WHERE (CASE 
            WHEN ltb.LearningTargetId = @learningTargetId and @learningTargetId is not null THEN 1
            WHEN ltb.CategoryId = @categoryId and @categoryId is not null THEN 1
            WHEN ltb.Grade = @grade and @grade is not null THEN 1
            WHEN ltb.SubjectId = @subjectId and @subjectId is not null THEN 1
            ELSE 0 END) = 1
) a

SQL高级查询 - select子句中单行聚合子查询的问题

5 个答案: