如何在SQL Server中获取此列结果

Question

希望尝试在SQL Server中返回下面的数据集。我有2列TrailerPosition＆amp;分频器和期待也返回区域。区域将计算为从区域1开始，然后在divider = 1之后将更改为记录上的区域2.然后在Divider = 1的下一条记录之后变为3.下面的屏幕截图看起来像我要返回的列

如何在SQL Server中完成此操作？

以下测试数据：

declare @t table (TrailerPosition nvarchar(5),Divider bit);
insert into @t values ('01L',0),('01R',0),('02L',0),('02R',1),('03L',1),('03R',0),('04L',0),('04R',0),('05L',1),('05R',1),('06L',0),('06R',0),('07L',0),('07R',0),('08L',0),('08R',0),('09L',0),('09R',0),('10L',0),('10R',0),('11L',0),('11R',0),('12L',0),('12R',0),('13L',0),('13R',0),('14L',0),('14R',0),('15L',0),('15R',0);

Answer 1

如果是2012+，窗口函数将非常适合

Select TrailerPosition
      ,Divider
      ,Zone    = 1+sum(Flag) over (Order By TrailerPosition)
 From (
        Select *
              ,Flag = case when Lag(Divider,1) over (Order By TrailerPosition) =1 and Divider=0 then 1 else 0 end
         From  YourTable
      ) A

<强>返回

Answer 2

因此，Zone = 1 +前一行的分频器值为0，前一行的分频器值为1.

<强>已更新

SELECT TrailerPosition, Divider,
     (SELECT COUNT(*) 
     FROM @MyTable T1
     WHERE (T1.TrailerPosition <= t0.TrailerPosition)
        AND (T1.Divider = 0)        
        AND (SELECT Divider 
             FROM @MyTable t2
             WHERE T2.TrailerPosition = 
                 (SELECT MAX(T3.TrailerPosition) 
                  FROM @MyTable T3 
                  WHERE T3.TrailerPosition < T1.TrailerPosition)) = 1) + 1 
                     AS Zone
 FROM @MyTable t0