如何找到最小的缺失序列号

问题描述 投票:3回答:3

我有一个有序列号的表。

我想找到缺失的序列号,这是缺少数字的最小值。

For eg.,

Seq No: 1,2,3,5,7,9 ==> Expected result: 4
Seq No: 1,2,3,4,5,6,7,9,15 ==> Expected result: 8
sql sql-server
3个回答
2
投票

你可以试试row_number()

with cte as
(
select seq,seq-row_number() over(order by seq) as diff
from tablename
)
select * from cte where diff<>0 and diff in (select min(diff) from cte where diff<>0)

2
投票

利用row_number()生成一个新序列,并将其与原始序列进行比较

select  min(new_seq)
from
(
    select  *, new_seq = row_number() over (order by seq)
    from    your_table
) t
where   seq <> new_seq

2
投票

选择序列号加1不存在的最小序列号,并添加一个:

select min(seqNo)+1 from SeqNoTable where seqNo+1 not in (select SeqNo from SeqNoTable)
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