Question

我在尝试从CASE语句中计算运行总计时遇到问题。我有两个表@report和@question以及两个变量@countCurrent和@countSuggested。

根据@report表中的数字与静态值或@question表中的值进行比较，我需要增加@countCurrent或@countSuggested。< / p>

这是我到目前为止所得到的，但不是在任何一列中得到5的组合，我只得到0/1。我认为这是JOIN的一部分，但我看不清楚。

declare @MinSuccessRate float,
        @countCurrent int,
        @countSuggested int

declare @report table
(
    intID   int identity(1,1),
    intReportID int,
    intParticipantID int,
    acceptable float,
    optimum float
)
insert @report
    select 1,1,.25,.75 union all
    select 1,2,.45,.75 union all
    select 1,3,.35,.75 union all
    select 1,4,.55,.75 union all
    select 1,5,.65,.75

declare @question table
(
    intID   int identity(1,1),
    intParticipantID    int,
    answer  float
)

insert @question
select 1,35 union all
select 1,55 union all
select 1,65 union all
select 1,75 union all
select 1,85

SET @MinSuccessRate=0.75
SET @countCurrent=0
SET @countSuggested=0

UPDATE @report
SET @countCurrent= 
    CASE WHEN acceptable>=@MinSuccessRate 
        THEN @countCurrent+1 
        ELSE 0 
        END,
    @countSuggested=
    CASE WHEN optimum*100 >=q.answer 
        THEN @countSuggested+1 
        ELSE 0 
        END
FROM @report pr 
    INNER JOIN @question q 
    ON pr.intParticipantID=q.intParticipantID
WHERE pr.intReportID=1

select @countCurrent [Current],@countSuggested [Suggested]

提前致谢！

Answer 1

在多表UPDATE中，每个目标记录最多可以更新一次（无论连接返回多少次）。

但是，您根本不需要UPDATE：

SELECT  @countCurrent =
        SUM
        (
        CASE
        WHEN acceptable >= @MinSuccessRate 
        THEN
                1
        ELSE
                0
        END
        ),
        @countSuggested =
        SUM
        (
        CASE
        WHEN optimum * 100 >= q.answer 
        THEN
                1
        ELSE
                0
        END
        )
FROM    @report pr 
JOIN    @question q 
ON      q.intParticipantID = pr.intParticipantID
WHERE   pr.intReportID = 1

Answer 2

您可以查看此http://www.1keydata.com/sql/sql-running-totals.html

在SQL Server中计算总计

2 个答案: