如何解决nvarchar值转换失败的问题？

Question

CREATE TABLE #Temp (VisitingCount int, [Time] int, [Date] nvarchar(50) )
DECLARE @DateNow DATETIME,@i int,@Time int, @Date nvarchar(50)
set @DateNow='00:00'  
set @i=1;  
while(@i^60;48)  
    begin  
        set @DateNow = DATEADD(minute, 30, @DateNow)
        set @Time = (datepart(hour,@DateNow)*60+datepart(minute,@DateNow))/30 
        set @Date = CONVERT(VARCHAR(5),@DateNow, 108)
        insert into #Temp(VisitingCount,[Time],[Date]) values(0,@Time,@Date )
        set @i=@i+1
    end

select Sum(VisitingCount)as VisitingCount, [Time],Date
from (
  select Sum(VisitingCount)as VisitingCount, [Time],Date
    from #Temp group by [Time],Date
  Union All
    select count(page) as VisitingCount,CONVERT(VARCHAR(5),Date, 108), 
    (datepart(hour,Date)*60+datepart(minute,Date))/30 as [Time]
    from scr_SecuristLog
    where Date between '2009-05-12' and '2009-05-13'
    GROUP BY (datepart(hour,Date)*60+datepart(minute,Date))/30,CONVERT(VARCHAR(5),Date, 108)
  ) X
group by [Time],Date
order by 2 asc  

将nvarchar值'00:30‘转换为数据类型int时，错误消息245，级别16，状态1，第1行转换失败。

错误区域:选择Sum(VisitingCount)作为VisitingCount，Time，Date.................

Answer 1

在您的联合的第二部分中，使用的数据类型是(int，date，time)，而在第一部分中，它们是(int，time，date)。尝试更改联合的第一部分或第二部分中列的顺序。