所以，我有一个表，通过下面给出的 SQL 描述
CREATE TABLE IF NOT EXISTS `employees` (
`e_id` int(10) unsigned NOT NULL AUTO_INCREMENT,
`e_username` varchar(100) NOT NULL,
`left_id` int(10) unsigned NOT NULL,
`right_id` int(10) unsigned NOT NULL,
`e_ssn` int(5) unsigned NOT NULL DEFAULT '0',
`e_first_name` varchar(100) NOT NULL,
`e_last_name` varchar(100) NOT NULL,
`e_address` text NOT NULL,
`e_location` int(10) unsigned DEFAULT NULL,
UNIQUE KEY `e_id` (`e_id`),
UNIQUE KEY `e_username` (`e_username`)
)
它有给定的数据
INSERT INTO `employees` (`e_id`, `e_username`, `left_id`, `right_id`, `e_ssn`, `e_first_name`, `e_last_name`, `e_address`, `e_location`) VALUES
(1, '100884', 1, 8, 444444444, 'James', 'Burnbridge', '1123 fdkjfjdkfjdfkjd', 76),
(2, '100885', 2, 7, 0, 'Frank', 'Grimsley', '123 Fayke St', 76),
(5, '100886', 3, 4, 0, 'Mark', 'Hill', 'kfjdkfjdf\r\nkofjdkfjdkfdj', 76),
(6, '100887', 5, 6, 0, 'fdfdfd', 'fdfdfd', 'fdfdfdf', 76);
我想创建一个触发器，这样当我输入新行时，就像这样
INSERT INTO employees(e_username,left_id,right_id,e_ssn, e_first_name, e_last_name, e_address, e_location)
VALUES('100888', 0, 0, 0, 'New','User', '100 NotReal st city, state zip', 76)
我希望 left_id 和 right_id 列根据其所在位置的第一个用户的 right_id 进行更新，该用户的 right_id 与 left_id 相差 1。
这是我到目前为止所拥有的，但它给了我一个错误
DROP TRIGGER IF EXISTS `after_insert_employees` ;
CREATE DEFINER = `root`@`localhost` TRIGGER `after_insert_employees` AFTER INSERT ON `employees`
FOR EACH
ROW BEGIN
DECLARE r_id INT;
SELECT max(right_id) INTO r_id FROM employees WHERE e_location=new.e_location AND right_id = left_id+1;
UPDATE employees SET left_id = r_id+1 AND right_id = r_id+2 WHERE e_id = new.e_id;
END
当我尝试插入某些东西时出现此错误
#1442 - Can't update table 'employees' in stored function/trigger because it is already used by statement which invoked this stored function/trigger.
我迷路了。有什么帮助吗？