使用数据透视表获取无效的列名称

I have this SQL:

我有这个SQL:

Select FirstName, LastName, Hours, Case When DatePart(Weekday, Date) = 1 
             Then Date - 6 
             Else Date - DatePart(Weekday, Date) + 2 
             End [WeekOf], IsNull([Week44], 0) as [Week44], IsNull([Week45], 0) as [Week45], IsNull([Week46], 0) as [Week46], IsNull([Week47], 0) as [Week47], IsNull([Week48], 0) as [Week48]
             from (
             Select FirstName, LastName, Hours, Date, 'Week' + 
             Case When DatePart(Weekday, Date) = 1 
             Then Cast(DatePart(ww, Date - 6) as nvarchar(max))
             Else Cast(DatePart(ww, Date - DatePart(Weekday, Date) + 2) as nvarchar(max))
             End WeekNo
             From Entry
             Where Date between '11/1/2013' and '11/30/2013'
             ) alpha
 pivot (
sum(Hours)
for WeekNo in ([week44], [week45], [week46], [week47], [week48])
) p
Select FirstName,