,  0.005),
 ( 6, 1, 1,    'one',    0.6,  0.006),
 ( 7, 2, NULL, 'n_one',  0.5,  0.007),
 ( 8, 2, 1,    'n_two',  NULL, 0.008),
 ( 9, 2, 2,    NULL,     0.7,  0.009),
 (10, 2, 0,    'n_four', 0.8,  0.010),
 (11, 2, 10,   NULL,     0.9,  NULL);

SELECT pk, LEAD(pk) OVER (ORDER BY pk) AS l,
 LEAD(pk,1) OVER (ORDER BY pk) AS l1,
 LEAD(pk,2) OVER (ORDER BY pk) AS l2,
 LEAD(pk,0) OVER (ORDER BY pk) AS l0,
 LEAD(pk,-1) OVER (ORDER BY pk) AS lm1,
 LEAD(pk,-2) OVER (ORDER BY pk) AS lm2
FROM t1;
+----+------+------+------+------+------+------+
| pk | l    | l1   | l2   | l0   | lm1  | lm2  |
+----+------+------+------+------+------+------+
|  1 |    2 |    2 |    3 |    1 | NULL | NULL |
|  2 |    3 |    3 |    4 |    2 |    1 | NULL |
|  3 |    4 |    4 |    5 |    3 |    2 |    1 |
|  4 |    5 |    5 |    6 |    4 |    3 |    2 |
|  5 |    6 |    6 |    7 |    5 |    4 |    3 |
|  6 |    7 |    7 |    8 |    6 |    5 |    4 |
|  7 |    8 |    8 |    9 |    7 |    6 |    5 |
|  8 |    9 |    9 |   10 |    8 |    7 |    6 |
|  9 |   10 |   10 |   11 |    9 |    8 |    7 |
| 10 |   11 |   11 | NULL |   10 |    9 |    8 |
| 11 | NULL | NULL | NULL |   11 |   10 |    9 |
+----+------+------+------+------+------+------+

URL: https://mariadb.com/kb/en/lead/https://mariadb.com/kb/en/lead/