在SQL Server中计算总数

Question

我在尝试从CASE语句中计算运行总数时遇到了问题。 我有两个表@report和@question和两个变量@countCurrent和@countSuggested。

根据@report表中与静态值或来自@question表的值进行比较的数字，我需要增加@countCurrent或@countSuggested。

这是我到目前为止，而不是得到任何一列5的组合，我只得到0/1。我认为这是JOIN的一部分，但我看不到。

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] 

在此先感谢！

Answer 1

在多台UPDATE，每个目标记录可以在更新最多一次（无论多少次它被加入返回）。

不过，你不需要UPDATE这里都：[复杂的SQL查询的运行总计列]

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

您可以检查此http://www.1keydata.com/sql/sql-running-totals.html