Question

这里我以小时和分钟得到“ProcessTime”，但是如果只有几秒钟，我会检查相反的情况（见下面的代码）

有什么办法可以改善吗？

select convert(varchar(10),ScanDate,101) as [Date], tmb.WO, tc.WOCategory, count(IdSingle) QtyProd, tb.Brand, tm.Model, 
        (case when (DateDiff(mi, Min(convert(varchar(10),ScanDate,8)), Max(convert(varchar(10),ScanDate,8)))/60%24 > 0) then 
            convert(varchar(5), DateDiff(mi, Min(convert(varchar(10),ScanDate,8)), Max(convert(varchar(10),ScanDate,8)))/60%24) + 'h '              
                else
            ''
        end) +
        (case when (DateDiff(mi, Min(convert(varchar(10),ScanDate,8)), Max(convert(varchar(10),ScanDate,8)))%60 > 0) then
            convert(varchar(5), DateDiff(mi, Min(convert(varchar(10),ScanDate,8)), Max(convert(varchar(10),ScanDate,8)))%60) + 'm'              
                else
            ''
        end) +          
        (case when 
            (DateDiff(mi, Min(convert(varchar(10),ScanDate,8)), Max(convert(varchar(10),ScanDate,8)))/60%24 <= 0) and 
            (DateDiff(mi, Min(convert(varchar(10),ScanDate,8)), Max(convert(varchar(10),ScanDate,8)))%60 <= 0) then 
            '< 1 min' 
            else 
            ''
        end) ProcessTime

Answer 1

使用SQL Server 2005，您可以使用CTE来改进此查询像这样：

;WITH minmax AS
(
   SELECT someKey, 
          DateDiff(mi, Min(convert(varchar(10),ScanDate,8)), Max(convert(varchar(10),ScanDate,8))) as mdiff
   FROM tablename
   GROUP BY fieldName
)
Select convert(varchar(10),ScanDate,101) as [Date], tmb.WO, tc.WOCategory, count(IdSingle) QtyProd, tb.Brand, tm.Model, 
        (case when (mdiff/60%24 > 0) then 
            convert(varchar(5), mdiff/60%24) + 'h '              
                else
            ''
        end) +
        (case when (mdiff%60 > 0) then
            convert(varchar(5), mdiff%60) + 'm'              
                else
            ''
        end) +          
        (case when 
            (DateDiff(mi, mdiff/60%24 <= 0) and (DateDiff(mi, mdiff%60 <= 0) then 
            '< 1 min' 
            else 
            ''
        end) ProcessTime
from tablename
join minmax on tablename.somekey = minmax.somekey

如何改进这个SQL查询

1 个答案: