Get integer which is not in database - mysql

Question

I have this MySQL table :
create table example (
My_Id INT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
My_Integer INT UNSIGNED DEFAULT 0
) ENGINE=InnoDB
Suppose this table to be populated like that :
SELECT * FROM `example`
My_Id My_Integer
1 10
2 1
3 3
4 152
5 16
6 481
7 128
My goal is to retrieve, from an user input, which integer is not in my table 'example'.
For example, if the user enter 1, 3, 10, the result should be empty.
If the user enter 1, 2, 3, 10, the result should be "2".
I can't find a way to do that, other than to do one MySQL request per integer in order to know if the number is in the table 'example'.
Do someone know a way ?

Answer 1

Select numberToMatch
from example as a
right outer join (
select 1 as numberToMatch union all
select 2 union all
select 3 union all
select 10
) as b
on b.numberToMatch = a.My_Integer
where a.My_Integer is null
Using right outer join and select those null record in the left table.

Answer 2

You could genereate tally table and use OUTER JOIN:
SELECT t.n
FROM (
SELECT a.N + b.N * 10 + c.N * 100 + 1 n
FROM (SELECT 0 AS N UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3
UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6
UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9) a
,(SELECT 0 AS N UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3
UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6
UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9) b
,(SELECT 0 AS N UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3
UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6
UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9) c
) t
LEFT JOIN example e
ON t.n = e.My_Integer
WHERE t.n IN (1,2,3,10) -- here goes numbers
AND e.My_Integer IS NULL;
LiveDemo
Output:
╔═══╗
║ n ║
╠═══╣
║ 2 ║
╚═══╝
It will work in range 1-999. You could expand it if needed.
Another way is to use UNION ALL:
SELECT s.col
FROM (SELECT 1 AS col
UNION ALL SELECT 2
UNION ALL SELECT 3
UNION ALL SELECT 10) AS s
LEFT JOIN example e
ON s.col = e.My_Integer
WHERE e.My_Integer IS NULL;
LiveDemo2