select id from info
id
-----------
1
2
3
5
6
7
8
10
11
12
15
(11 行受影响)
方法一：
select (select max(id)+1 from Info where id<a.id) as beginId,(id-1) as endId
from Info a
where
a.id>(select max(id)+1 from Info where id<a.id)
beginId endId
----------- -----------
4 4
9 9
13 14
(3 行受影响)
方法二：
select beginId,(select min(id)-1 from info where id > beginId) as endId
from (
select id+1 as beginId from info where id+1 not in (select id from info) and id < (select max(id) from info)
) as t
beginId endId
----------- -----------
4 4
9 9
13 14
(3 行受影响)
说明：
1、查找结果的两列是断号的区间，如果beginId=endId，则表示缺少该号码，否则表示缺少beginId ~ endId；
2、如果号码1不存在，区间1 ~ select min(id)-1 from info 将无法找出