我有以下一堆代码试图使用两个游标更新一个字段,一个游标在另一个游标中。我使用第一个光标只是为了获取一个 id 值(第一个光标),然后我得到一个基于该 id 的其他 id 值的列表(第二个光标)。问题是第二个游标的结果集包含最后一个 id 两次!我找不到错误!循环中的某些内容,2 个游标的终止变量中的某些内容?
欢迎任何帮助!提前致谢!
DELIMITER $$ DROP PROCEDURE IF EXISTS updateNumberOfPoisForPlacesWithChildren$$ CREATE PROCEDURE updateNumberOfPoisForPlacesWithChildren() BEGIN DECLARE single_place_id INT(11); 声明 single_unique_parents_id INT(11); 声明完成,temp_number_of_pois,sum_number_of_pois INT DEFAULT 0;
DECLARE unique_parents_ids CURSOR FOR SELECT DISTINCT `parent_id` FROM `places` WHERE `parent_id` IS NOT NULL;
DECLARE temp_places_ids CURSOR FOR SELECT `id` FROM `places` WHERE `parent_id` = single_unique_parents_id;
DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = 1;
OPEN unique_parents_ids;
main_loop_for_parent_ids : LOOP
SET sum_number_of_pois = 0;
IF done = 1 THEN
CLOSE unique_parents_ids;
LEAVE main_loop_for_parent_ids;
END IF;
IF NOT done = 1 THEN
FETCH unique_parents_ids INTO single_unique_parents_id;
OPEN temp_places_ids;
main_loop_for_places : LOOP
IF done = 1 THEN
CLOSE temp_places_ids;
LEAVE main_loop_for_places;
END IF;
IF NOT done = 1 THEN
FETCH temp_places_ids INTO single_place_id;
SELECT COUNT(`id`) INTO temp_number_of_pois FROM `pois` WHERE `place_id` = single_place_id;
SET sum_number_of_pois = sum_number_of_pois + temp_number_of_pois;
END IF;
END LOOP;
UPDATE `places` SET `number_of_pois`=sum_number_of_pois WHERE `id` = single_unique_parents_id;
END IF;
END LOOP;
END$$
分隔符;