Question

我必须测试表中的序列并且必须删除错误的记录。例如：

 DATE                DriverId CodeId
 2014/03/01 14:00:00, 7168,     22     -- GO
 2014/03/01 14:30:00, 7168,     23     -- STOP
 2014/03/01 14:40:00, 7168,     22     -- GO
 2014/03/01 15:10:00, 7168,     22     -- GO     <--- delete this record
 2014/03/01 16:00:00, 7168,     23     -- STOP

当我删除了worng记录时，我必须计算GO＆amp;之间的时间。停止

我正在使用SQL Server 2012

Answer 1

假设日期具有序列顺序，似乎您要删除值与前一个值相同的那个：

with todelete as (
      select t.*, lag(codeid) over (order by "date") as prev_codeid
      from table t
)
delete from todelete
    where prev_codeid = codeid;

这是SQL Server 2012语法。您可以在早期版本中使用相关子查询执行此操作：

with todelete as (
      select t.*,
             (select top 1 codeid
              from table t2
              where t2."date" < t."date"
              order by t2.date desc
             ) as prev_codeid
      from table t
)
delete from todelete
    where prev_codeid = codeid;

如何控制序列？

1 个答案: