查找连续序列并建议序列中的下一个数字

Question

我正在尝试创建一个程序来：

• 接受任何数字作为输入，例如102
• 找到它所属的序列范围，例如100 to 103
• 返回建议的下一个号码给用户，例如104

该表本身看起来像这样：

数量
100
101
102
103
110
111
112
113
114
115
120
121

理想情况下，查询的输出将返回如下内容：

开始	结尾	下一个编号
100	103	104
110	115	116
120	121	122

我正在尝试做的事情与某种间隙和岛屿技术有关。我想从这里尝试一些东西，但无法完全发挥作用。 间隙和岛屿链接

这就是我尝试想出的...

WITH cteSource(ID, Seq, Num)
AS(
    SELECT d.ID, f.Seq, f.Num
    FROM (
        SELECT 
            ID,
            ROW_NUMBER() OVER (PARTITION BY ID ORDER BY MIN(SeqNo)) AS Grp,
            MIN(SeqNo) AS StartSeqNo,
            MAX(SeqNo) AS EndSeqNo
        FROM
            (
            SELECT 1 ID, Num SeqNo, 
               Num - ROW_NUMBER() OVER (PARTITION BY 1 ORDER BY Num) AS RN
            FROM 
            Number
            ) AS a
        GROUP BY ID, RN
        ) d
    CROSS APPLY (
            VALUES (d.Grp, d.EndSeqNo + 1),(d.Grp -1, d.StartSeqNo -1)
            ) AS f(Seq, Num)
)
SELECT ID, MIN(Num) AS StartSeqNo, MAX(Num) AS EndSeqNo, MAX(Num) + 1 as NextNr
FROM cteSource
GROUP BY ID, Seq
HAVING COUNT(*) = 2

结果如下：

起始序列号	结束序列号	下一个号码
104	109	110
116	119	120

这是设置：

CREATE TABLE [dbo].[Number](
    [Num] [int] NULL
) 
GO

INSERT INTO Number
(Num)
VALUES
(100),
(101),
(102),
(103),
(110),
(111),
(112),
(113),
(114),
(115),
(120),
(121)

Answer 1

也许这会有所帮助。

Select [Start]  = min(num)
      ,[End]    = max(num)
      ,[NextNr] = max(num) + 1
 From (
        Select * 
              ,Grp = num - row_number() over (order by num)
         From  number
      ) A
 Group By Grp

结果

Start   End     NextNr
100     103     104
110     115     116
120     121     122