判断时间段内有几个休息期

declare   @b   datetime,@e   datetime  
  set   @b   =   '2003-12-20'  
  set   @e   =   '2004-01-21'  
   
  select   datediff(week,@b,@e)  
  ,datediff(week,@b,@e)   +   case   when   datepart(weekday,@b)   >   1   then   0   else   1   end   -   case   when   datepart(weekday,@e)   >=   1   then   0   else   1   end   as   周日数  
  ,datediff(week,@b,@e)   +   case   when   datepart(weekday,@b)   >   2   then   0   else   1   end   -   case   when   datepart(weekday,@e)   >=   2   then   0   else   1   end   as   周一数  
  ,datediff(week,@b,@e)   +   case   when   datepart(weekday,@b)   >   3   then   0   else   1   end   -   case   when   datepart(weekday,@e)   >=   3   then   0   else   1   end   as   周二数  
  ,datediff(week,@b,@e)   +   case   when   datepart(weekday,@b)   >   4   then   0   else   1   end   -   case   when   datepart(weekday,@e)   >=   4   then   0   else   1   end   as   周三数  
  ,datediff(week,@b,@e)   +   case   when   datepart(weekday,@b)   >   5   then   0   else   1   end   -   case   when   datepart(weekday,@e)   >=   5   then   0   else   1   end   as   周四数  
  ,datediff(week,@b,@e)   +   case   when   datepart(weekday,@b)   >   6   then   0   else   1   end   -   case   when   datepart(weekday,@e)   >=   6   then   0   else   1   end   as   周五数  
  ,datediff(week,@b,@e)   +   case   when   datepart(weekday,@b)   >   7   then   0   else   1   end   -   case   when   datepart(weekday,@e)   >=   7   then   0   else   1   end   as   周六数