MySQL 存储过程 递归 获取所有子节点

数据表是这样的：

create table BAT_STEP_RELY (step_id char(5),rely_step_id char(5));

测试数据：

INSERT INTO `bat_step_rely` (`step_id`, `rely_step_id`) VALUES ('2', '1');INSERT INTO `bat_step_rely` (`step_id`, `rely_step_id`) VALUES ('3', '1');INSERT INTO `bat_step_rely` (`step_id`, `rely_step_id`) VALUES ('4', '2');INSERT INTO `bat_step_rely` (`step_id`, `rely_step_id`) VALUES ('5', '4');INSERT INTO `bat_step_rely` (`step_id`, `rely_step_id`) VALUES ('6', '5');INSERT INTO `bat_step_rely` (`step_id`, `rely_step_id`) VALUES ('7', '4');INSERT INTO `bat_step_rely` (`step_id`, `rely_step_id`) VALUES ('7', '8');INSERT INTO `bat_step_rely` (`step_id`, `rely_step_id`) VALUES ('8', '3');INSERT INTO `bat_step_rely` (`step_id`, `rely_step_id`) VALUES ('9', '1');INSERT INTO `bat_step_rely` (`step_id`, `rely_step_id`) VALUES ('9', '8');

建一个临时的表：

create table temp_results (step_id char(5),rely_step_id char(5));

存储过程是这样的：

DROP PROCEDURE IF EXISTS getSteps;CREATE PROCEDURE getSteps(IN pid char(5))BEGINDECLARE done INT DEFAULT FALSE;DECLARE id char(5);DECLARE cur1 CURSOR FOR SELECT STEP_ID FROM BAT_STEP_RELY WHERE RELY_STEP_ID=pid;DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;set max_sp_recursion_depth = 100;OPEN cur1;read_loop: LOOPFETCH cur1 INTO id;IF done THENLEAVE read_loop;END IF;INSERT INTO temp_results values (id, pid);call getSteps(id);END LOOP;CLOSE cur1;END;

获取所有子节点：

TRUNCATE TABLE temp_results;call getSteps('1');SELECT STEP_ID FROM TEMP_RESULTS GROUP BY STEP_ID;