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SQL Window Functions: Find next id for every row in result set ("holes" in ids included)
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USE test; | |
DROP TABLE IF EXISTS `employee`; | |
CREATE TABLE `employee` ( | |
`id` INT UNSIGNED NOT NULL AUTO_INCREMENT, | |
`name` VARCHAR(45) NULL, | |
`manager_id` INT UNSIGNED NOT NULL, | |
PRIMARY KEY (`id`)); | |
INSERT INTO `employee` (`name`, `manager_id`) VALUES ('Dev1', '17'); -- 1 | |
INSERT INTO `employee` (`name`, `manager_id`) VALUES ('Dev2', '17'); -- 2 | |
INSERT INTO `employee` (`name`, `manager_id`) VALUES ('Dev3', '17'); -- 3 | |
INSERT INTO `employee` (`name`, `manager_id`) VALUES ('Dev4', '17'); -- 4 | |
INSERT INTO `employee` (`name`, `manager_id`) VALUES ('Dev4', '17'); -- 5 | |
INSERT INTO `employee` (`name`, `manager_id`) VALUES ('Dev5', '18'); -- 6 | |
INSERT INTO `employee` (`name`, `manager_id`) VALUES ('Dev5', '18'); -- 7 | |
INSERT INTO `employee` (`name`, `manager_id`) VALUES ('Dev6', '19'); -- 8 | |
INSERT INTO `employee` (`name`, `manager_id`) VALUES ('Dev6', '19'); -- 9 | |
INSERT INTO `employee` (`name`, `manager_id`) VALUES ('Dev7', '19'); -- 10 | |
INSERT INTO `employee` (`name`, `manager_id`) VALUES ('Dev8', '18'); -- 11 | |
INSERT INTO `employee` (`name`, `manager_id`) VALUES ('Marketer1', '16'); -- 12 | |
INSERT INTO `employee` (`name`, `manager_id`) VALUES ('Marketer2', '16'); -- 13 | |
INSERT INTO `employee` (`name`, `manager_id`) VALUES ('CEO', '0'); -- 14 | |
INSERT INTO `employee` (`name`, `manager_id`) VALUES ('Managers Director', '14'); -- 15 | |
INSERT INTO `employee` (`name`, `manager_id`) VALUES ('Marketing Director', '14'); -- 16 | |
INSERT INTO `employee` (`name`, `manager_id`) VALUES ('Manager1', '15'); -- 17 | |
INSERT INTO `employee` (`name`, `manager_id`) VALUES ('Manager2', '15'); -- 18 | |
INSERT INTO `employee` (`name`, `manager_id`) VALUES ('Manager3', '15'); -- 19 | |
DELETE FROM `employee` WHERE `id` IN (4,6,8); -- delete repeated records, make "holes" in ids |
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id | name | manager_id | next_id | |
---|---|---|---|---|
1 | Dev1 | 17 | 2 | |
2 | Dev2 | 17 | 3 | |
3 | Dev3 | 17 | 5 | |
5 | Dev4 | 17 | 7 | |
7 | Dev5 | 18 | 9 | |
9 | Dev6 | 19 | 10 | |
10 | Dev7 | 19 | 11 | |
11 | Dev8 | 18 | 12 | |
12 | Marketer1 | 16 | 13 | |
13 | Marketer2 | 16 | 14 | |
14 | CEO | 0 | 15 | |
15 | Managers Director | 14 | 16 | |
16 | Marketing Director | 14 | 17 | |
17 | Manager1 | 15 | 18 | |
18 | Manager2 | 15 | 19 | |
19 | Manager3 | 15 | NULL |
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USE test; | |
SELECT id, name, manager_id, | |
LEAD(id) OVER(ORDER BY id ASC RANGE BETWEEN CURRENT ROW AND 2 FOLLOWING) as next_id | |
FROM employee | |
ORDER BY id ASC |
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