SQL Server：时间的十进制差异

Question

我正在尝试转换小数小时时差，但总是四舍五入导致问题。

declare @Accrued decimal(9,4) = 24.60
declare @Used decimal(9,4) = 23.5734
declare @Remaining decimal(9,2) = @Accrued -  @Used

declare @RoundAccrued decimal(9,2) = ceiling(@Accrued * 100) /  100
declare @RoundUsed decimal(9,2) =  ceiling(@Used * 100) /  100
declare @RoundRemaining decimal(9,2) =  ceiling(@Remaining * 100) /  100

declare @hrAcc int = @Accrued
select left(cast (@hrAcc as varchar), 4) + '.' + right('0' + cast((floor((@RoundAccrued * 60) % 60)) as varchar), 2) Accrued

declare @hrUsed int = @Used
select left(cast (@hrUsed as varchar), 4) + '.' + right('0' + cast((floor((@RoundUsed * 60) % 60)) as varchar), 2) Used
declare @hrRem int = @Remaining
select  left(cast (@hrRem as varchar), 4) + '.' + right('0' + cast((floor((@RoundRemaining * 60) % 60)) as varchar), 2) Remaining

结果

• 应计：24.36
• 使用时间：23.34
• 剩余：1.01（而不是 1.02）

它在Accrued 和Used 上完美运行，但无论我做什么，它仍然比不同的时间短一分钟或更多。

Answer 1

这一切都是因为使用了圆角、天花板和地板。

您可以使用以下内容：

select convert(varchar(10), @hrAcc) + '.'+ right('0' + cast(cast((@Accrued-@hrAcc)*60 as int) as varchar),2)
select convert(varchar(10), @hrUsed) + '.'+ right('0' + cast(cast((@Used-@hrUsed)*60 as int) as varchar),2)
select cast((abs(cast(@hrAcc*60+cast((@Accrued-@hrAcc)*60 as int) as int) - cast(@hrUsed*60+cast((@Used-@hrUsed)*60 as int) as int)))/60 as varchar)
    +'.'
    + cast((abs(cast(@hrAcc*60+cast((@Accrued-@hrAcc)*60 as int) as int) - cast(@hrUsed*60+cast((@Used-@hrUsed)*60 as int) as int)))%60 as varchar)

---测试（使用舍入值而不是原始值）

 declare @Accrued decimal(9,4) = 0.5333--106.325--106.325--51.2568--49.9217--106.325--49.9217--24.60
    declare @Used decimal(9,4) = 0.0333--87.885--87.885--49.9217--51.2568--87.88--51.2568--23.5734
    declare @Remaining decimal(9,4) = @Accrued -  @Used
declare @hrAcc int = @Accrued
declare @hrUsed int = @Used
declare @hrRem int = @Remaining 

declare @RoundAccrued decimal(9,4) = ceiling(@Accrued * 100) /  100
declare @RoundUsed decimal(9,4) =  ceiling(@Used * 100) /  100
declare @RoundRemaining decimal(9,4) =  ceiling(@Remaining * 100) /  100

select convert(varchar(10), @hrAcc) + '.'+ right('0' + cast(cast((@RoundAccrued-@hrAcc)*60 as int) as varchar),2) Accrued
select convert(varchar(10), @hrUsed) + '.'+ right('0' + cast(cast((@RoundUsed-@hrUsed)*60 as int) as varchar),2) Used
select cast((abs(cast(@hrAcc*60+cast((@RoundAccrued-@hrAcc)*60 as int) as int) - cast(@hrUsed*60+cast((@RoundUsed-@hrUsed)*60 as int) as int)))/60 as varchar)
    +'.'
    + cast((abs(cast(@hrAcc*60+cast((@RoundAccrued-@hrAcc)*60 as int) as int) - cast(@hrUsed*60+cast((@RoundUsed-@hrUsed)*60 as int) as int)))%60 as varchar) Remaining

Answer 2

使用秒应该足够了。所以试试这个：

select cast(dateadd(second, @Remaining*60*60, 0) as time)

这将结果作为时间数据类型。请注意，此类型仅限于 24 小时。