欠番検索
前提
SELECT * FROM t1;
+------+
| id |
+------+
| 1 |
| 2 |
| 4 |
+------+
3 rows in set (0.00 sec)
3が欠番になっている。
欠番検索
SELECT id + 1 FROM t1 WHERE (id + 1) NOT IN ( SELECT id FROM t1 ) ;
+--------+
| id + 1 |
+--------+
| 3 |
| 5 |
+--------+
2 rows in set (0.01 sec)