Sql server T-sql在字段更改时重置行号_Sql Server_Tsql_Sql Server 2005_Reset_Row Number

Sql server T-sql在字段更改时重置行号

sql-server tsql sql-server-2005

Sql server T-sql在字段更改时重置行号,sql-server,tsql,sql-server-2005,reset,row-number,Sql Server,Tsql,Sql Server 2005,Reset,Row Number,与我最近的一篇文章“t-sql sequential duration”类似，但并不完全相同，我想根据x列（在我的例子中是“who”列）中的更改重置行号下面是第一个返回原始（ish）数据小样本的查询：第二步是添加行号（我在第一次查询中没有这样做，因为使用了DISTINCT这个词）；所以下一步是我遇到的问题：目标是在“who”列中的值每次更改时将RowID重置为1。下面的代码得到了一个“几乎就在那里”的结果（应该注意的是，我从某个地方偷了/借用了这段代码，但现在我找不到该网站）：预期结果：

与我最近的一篇文章“t-sql sequential duration”类似，但并不完全相同，我想根据x列（在我的例子中是“who”列）中的更改重置行号

下面是第一个返回原始（ish）数据小样本的查询：

第二步是添加行号（我在第一次查询中没有这样做，因为使用了DISTINCT这个词）；所以

下一步是我遇到的问题：目标是在“who”列中的值每次更改时将RowID重置为1。下面的代码得到了一个“几乎就在那里”的结果（应该注意的是，我从某个地方偷了/借用了这段代码，但现在我找不到该网站）：

预期结果：

Row custno      moddate                     who
1   581827      2012-11-08 08:38:00.000     EMSZC14
2   581827      2012-11-08 08:41:10.000     EMSZC14
3   581827      2012-11-08 08:53:46.000     EMSZC14
4   581827      2012-11-08 08:57:04.000     EMSZC14
5   581827      2012-11-08 08:58:35.000     EMSZC14
6   581827      2012-11-08 08:59:13.000     EMSZC14
7   581827      2012-11-08 09:00:06.000     EMSZC14
1   581827      2012-11-08 09:04:39.000     EMSZC49 Reset row number to 1 
2   581827      2012-11-08 09:05:04.000     EMSZC49
3   581827      2012-11-08 09:06:32.000     EMSZC49
4   581827      2012-11-08 09:12:03.000     EMSZC49
5   581827      2012-11-08 09:12:38.000     EMSZC49
6   581827      2012-11-08 09:14:18.000     EMSZC49
1   581827      2012-11-08 09:17:35.000     EMSZC14 Reset row number to 1

感谢您的帮助。

请不要：

PARTITION BY custno ORDER BY custno, moddate, who)

尝试：

我能想到的唯一解决方案是使用游标（ugh）并经历RBAR过程。这不是一个优雅的解决方案，因为光标必须读取超过1m行的数据。Bummer.

如果您使用的是SQL Server 2012，则可以使用将值与前一行进行比较，并可以使用和记录更改

with C1 as
(
  select custno,
         moddate,
         who,
         lag(who) over(order by moddate) as lag_who
  from chr
),
C2 as
(
  select custno,
         moddate,
         who,
         sum(case when who = lag_who then 0 else 1 end) 
            over(order by moddate rows unbounded preceding) as change 
  from C1
)
select row_number() over(partition by change order by moddate) as RowID,
       custno,
       moddate,
       who
from C2

更新：

SQL Server 2005的版本。它使用递归CTE和临时表作为需要迭代的数据的中间存储

create table #tmp
(
  id int primary key,
  custno int not null,
  moddate datetime not null,
  who varchar(10) not null
);

insert into #tmp(id, custno, moddate, who)
select row_number() over(order by moddate),
       custno,
       moddate,
       who
from chr;

with C as
(
  select 1 as rowid,
         T.id,
         T.custno,
         T.moddate,
         T.who,
         cast(null as varchar(10)) as lag_who
  from #tmp as T
  where T.id = 1
  union all
  select case when T.who = C.who then C.rowid + 1 else 1 end,
         T.id,
         T.custno,
         T.moddate,
         T.who,
         C.who
  from #tmp as T
    inner join C
      on T.id = C.id + 1
)
select rowid,
       custno,
       moddate,
       who
from C
option (maxrecursion 0);

drop table #tmp;

我使用Rank（）成功解决了这个问题：

这将返回您想要的结果。我发现这篇文章试图解决同样的问题

已经尝试过了（它似乎应该可以工作，不是吗？），但它仍然返回相同的结果集，最后一行号为14。不过，还是要不断地向我抛主意。我确信我只是错过了一些简单的步骤。不幸的是，我们仍在运行2005年，计划下个月升级到2008R2。滞后函数将是这个问题的一个干净的解决方案。感谢您让我注意到这一点……这只是迁移到SQL Server 2012的另一个理由。非常酷的解决方案。我唯一关心的（事实上并没有发现）是在maxrecursion中使用0。这可能会导致一个无限循环，但在考虑我的数据结构时，可能不会考虑我得到的数据。非常感谢。这个滞后函数正是我需要的！非常感谢。

WITH c1 AS (
        SELECT      DISTINCT chr.custno,
                    CAST(LEFT(CONVERT( VARCHAR(20),chr.moddate,112),10)+ ' ' + chr.modtime AS DATETIME)as moddate,
                    chr.who
        FROM        <TABLE> chr 
        WHERE       chr.custno = 581827
                    AND LEFT(chr.who, 5) = 'EMSZC'
                    AND chr.[description] NOT LIKE 'Recalled and viewed this customer'
        )
, c1a AS    (
            SELECT  ROW_NUMBER() OVER (PARTITION BY custno ORDER BY custno, moddate, who) AS RowID, custno, moddate, who
            FROM    c1
            )

SELECT  x.RowID - y.MinID + 1 AS Row,
        x.custno, x.Touch, x.moddate, x.who      
FROM    (
            SELECT  custno, who, MIN(RowID) AS MinID
            FROM    c1a
            GROUP BY custno, who
        ) AS y
        INNER JOIN c1a x ON x.custno = y.custno AND x.who = y.who

Row custno      moddate                    who
1   581827      2012-11-08 08:38:00.000     EMSZC14
2   581827      2012-11-08 08:41:10.000     EMSZC14
3   581827      2012-11-08 08:53:46.000     EMSZC14
4   581827      2012-11-08 08:57:04.000     EMSZC14
5   581827      2012-11-08 08:58:35.000     EMSZC14
6   581827      2012-11-08 08:59:13.000     EMSZC14
7   581827      2012-11-08 09:00:06.000     EMSZC14
1   581827      2012-11-08 09:04:39.000     EMSZC49 Reset row number to 1 (Hooray! It worked!)
2   581827      2012-11-08 09:05:04.000     EMSZC49
3   581827      2012-11-08 09:06:32.000     EMSZC49
4   581827      2012-11-08 09:12:03.000     EMSZC49
5   581827      2012-11-08 09:12:38.000     EMSZC49
6   581827      2012-11-08 09:14:18.000     EMSZC49
14  581827      2012-11-08 09:17:35.000     EMSZC14 Reset row number to 1 (Crappies.)

Row custno      moddate                     who
1   581827      2012-11-08 08:38:00.000     EMSZC14
2   581827      2012-11-08 08:41:10.000     EMSZC14
3   581827      2012-11-08 08:53:46.000     EMSZC14
4   581827      2012-11-08 08:57:04.000     EMSZC14
5   581827      2012-11-08 08:58:35.000     EMSZC14
6   581827      2012-11-08 08:59:13.000     EMSZC14
7   581827      2012-11-08 09:00:06.000     EMSZC14
1   581827      2012-11-08 09:04:39.000     EMSZC49 Reset row number to 1 
2   581827      2012-11-08 09:05:04.000     EMSZC49
3   581827      2012-11-08 09:06:32.000     EMSZC49
4   581827      2012-11-08 09:12:03.000     EMSZC49
5   581827      2012-11-08 09:12:38.000     EMSZC49
6   581827      2012-11-08 09:14:18.000     EMSZC49
1   581827      2012-11-08 09:17:35.000     EMSZC14 Reset row number to 1

PARTITION BY custno ORDER BY custno, moddate, who)

PARTITION BY custno, who ORDER BY custno, moddate)

with C1 as
(
  select custno,
         moddate,
         who,
         lag(who) over(order by moddate) as lag_who
  from chr
),
C2 as
(
  select custno,
         moddate,
         who,
         sum(case when who = lag_who then 0 else 1 end) 
            over(order by moddate rows unbounded preceding) as change 
  from C1
)
select row_number() over(partition by change order by moddate) as RowID,
       custno,
       moddate,
       who
from C2

create table #tmp
(
  id int primary key,
  custno int not null,
  moddate datetime not null,
  who varchar(10) not null
);

insert into #tmp(id, custno, moddate, who)
select row_number() over(order by moddate),
       custno,
       moddate,
       who
from chr;

with C as
(
  select 1 as rowid,
         T.id,
         T.custno,
         T.moddate,
         T.who,
         cast(null as varchar(10)) as lag_who
  from #tmp as T
  where T.id = 1
  union all
  select case when T.who = C.who then C.rowid + 1 else 1 end,
         T.id,
         T.custno,
         T.moddate,
         T.who,
         C.who
  from #tmp as T
    inner join C
      on T.id = C.id + 1
)
select rowid,
       custno,
       moddate,
       who
from C
option (maxrecursion 0);

drop table #tmp;

SELECT RANK() OVER (PARTITION BY who ORDER BY custno, moddate) AS RANK