按顺序的数字分组

Question

我有一些这样的数据：

row    id
1      1
2      36
3      37
4      38
5      50
6      51

我想查询它看起来像这样：

 row    id    group
 1      1     1
 2      36    2
 3      37    2
 4      38    2
 5      50    3
 6      51    3

... 这样我就可以在数字连续的地方进行 GROUP BY。

另外，循环/游标是不可能的，因为我正在处理大量数据，谢谢。

Answer 1

;WITH firstrows AS
(
    SELECT id, ROW_NUMBER() OVER (ORDER BY id) groupid
    FROM Table1 a
    WHERE id - 1 NOT IN (SELECT b.id FROM Table1 b)
)
SELECT id, 
    (
        SELECT MAX(b.groupid)
        FROM firstrows b
        WHERE b.id <= a.id
    ) groupid
FROM Table1 a

Answer 2

with
  data(row, id) as (
    select * 
    from (
      values
       (1,1)
      ,(2,36)
      ,(3,37)
      ,(4,38)
      ,(5,50)
      ,(6,51)
    ) as foo(row, id)
  ),
  anchor(row, id) as (
    select row, id
    from data d1
    where not exists(select 0 from data d2 where d2.id = d1.id - 1)
  )
select d1.*, dense_rank() over(order by foo.id) as thegroup
from
  data d1
  cross apply (select max(id) from anchor where anchor.id <= d1.id) as foo(id)
order by
  d1.row
  ;

Answer 3

在row 值的序列中可能存在间隙并且假设这些间隙应该被忽略的基础上，此解决方案做了更多的工作，这是绝对必要的。

设置测试数据：

DECLARE @table TABLE
(ROW INT,
id INT
)

INSERT @table
SELECT 1,1
UNION SELECT 2,36
UNION SELECT 3,37
UNION SELECT 4,38
UNION SELECT 5,50
UNION SELECT 6,51

输出查询

;WITH grpCTE
AS
(
    SELECT ROW, id,
    ROW_NUMBER() OVER (ORDER BY ROW
                        ) AS rn
    FROM @table
)
,recCTE
AS
(
    SELECT ROW, id, rn, 1 AS grp
    FROM grpCTE
    WHERE rn = 1

    UNION ALL

    SELECT g.row, g.id, g.rn, CASE WHEN g.id = r.id + 1 THEN r.grp ELSE r.grp + 1 END AS grp
    FROM grpCTE AS g
    JOIN recCTE AS r
    ON g.rn = r.rn + 1
)
SELECT row, id, grp FROM recCTE

Answer 4

create table #temp
(
    IDUnique int Identity(1,1),
    ID int, 
    grp int
)


Insert into #temp(ID) Values(1)
Insert into #temp(ID) Values(36)
Insert into #temp(ID) Values(37)
Insert into #temp(ID) Values(38)
Insert into #temp(ID) Values(50)
Insert into #temp(ID) Values(51)

declare @IDUnique int
declare @PreviousUnique int
declare @ID int
declare @grp int
declare @Previous int
declare @Row int

DECLARE @getAccountID CURSOR SET @getAccountID = CURSOR FOR SELECT Row_Number() Over(Order by IDUnique) Row, IDUnique, ID  From #temp
OPEN @getAccountID
FETCH NEXT FROM @getAccountID INTO @Row, @IDUnique, @ID 
WHILE @@FETCH_STATUS = 0
BEGIN
    IF(@Row = 1)
    Begin
        update #temp set grp = 1 Where IDUnique = @IDUnique
        set @Previous = @ID
        set @grp = 1
    End
    Else If (@Previous + 1 = @ID)
    Begin
        update #temp set grp = @grp Where IDUnique = @IDUnique
        set @Previous = @ID
    End
    Else
    Begin
        set @Previous = @ID
        set @grp = @grp + 1
        update #temp set grp = @grp Where IDUnique = @IDUnique
    End
    FETCH NEXT FROM @getAccountID INTO @Row, @IDUnique, @ID
END
CLOSE @getAccountID
DEALLOCATE @getAccountID

Select * from #temp
Drop Table #temp

Answer 5

 Select T.Id, T.Row, groupId as "Group", dr  FROM tbrows T
Left Outer Join
    (
    Select min(id) as groupId,DENSE_RANK() over( order by min(id)) as dr, MIN(row-id) as d, Sum(1) as s FROM tbrows
         Group BY (row-id)
    ) U
On (T.Id >= U.groupId) and (T.Id < U.groupId+U.s)
Order By T.Id