MySQL finding gaps in column with multiple ID - mysql

Question

I would like to find gaps in following table:
create table sequence
(
`Id` int,
`Value` int not null,
PRIMARY KEY (`Id`,`Value`)
);
insert into sequence
( `Id`, `Value` )
values
(10, 0 ),
(10, 1 ),
(10, 4 ),
(10, 5 ),
(10, 6 ),
(10, 7 ),
(11, 0 ),
(11, 1 ),
(11, 2 ),
(11, 5 ),
(11, 7 );
Expeced result is somthing like:
10 | 2-3
11 | 3-4
11 | 6
or
10 | 2
10 | 3
11 | 3
11 | 4
11 | 6
I know, that value of the colum 'Value' is between 0 and 7.
Is it possible to do it using MySQL?
EDIT 1
Based on answers I come with this:
SELECT Tbl1.Id,
startseqno,
Min(B.Value) - 1 AS END
FROM (SELECT Id,
Value + 1 AS StartSeqNo
FROM SEQUENCE AS A
WHERE NOT EXISTS (SELECT *
FROM SEQUENCE AS B
WHERE B.Id = A.id
AND B.Value = A.Value + 1)
AND Value < (SELECT Max(Value)
FROM SEQUENCE B
WHERE B.Id = A.Id)) AS Tbl1,
SEQUENCE AS B
WHERE B.Id = Tbl1.Id
AND B.Value > Tbl1.startseqno
But now I am getting just
10 | 2 | 3
Please, does somebody know, how to fix it?
sqlfiddle

Answer 1

You can do this with not exists:
select s.*
from sequence s
where not exists (select 1 from sequence s2 where s2.id = s.id and s2.value = s.value + 1) and
exists (select 1 from sequence s2 where s2.id = s.id and s2.value > s.value);
The exists clause is important so you don't report the final value for each id.
EDIT:
Here is a better approach:
select s.value + 1 as startgap,
(select min(s2.value) - 1 from sequence s2 where s2.id = s.id and s2.value > s.value) as endgap
from sequence s
where not exists (select 1 from sequence s2 where s2.id = s.id and s2.value = s.value + 1) and
exists (select 1 from sequence s2 where s2.id = s.id and s2.value > s.value);