首先除了po以外,还需要一个dto,dto需要extends po,同时内包含一个List<dto>childTreeNodes属性 service层方法:获取当前节点的所有子节点后,通过遍历所有节点,依次构造树形关系 publicList<CourseCategoryTreeDto>queryTreeNodes(String id) { List<CourseCategoryTreeDto>co
#定义递归查询query = """ WITH RECURSIVE tree AS ( SELECT id, name, parent_id FROM your_table WHERE parent_id IS NULL UNION ALL SELECT child.id, child.name, child.parent_id FROM your_table child INNER JOIN tree parent ON child.parent_id = parent.id ) SELECT id, name, parent_id FR...
SELECT GROUP_CONCAT(id) INTO child_ids FROM tree_table WHERE parent_id = node_id; IF child_ids IS NOT NULL THEN SET child_ids = CONCAT(child_ids, ',', get_all_children(child_id)); END IF; RETURN child_ids; END$$ DELIMITER ; 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12...
WITH RECURSIVE child_tree AS ( -- 初始查询:选择目标节点 SELECT id, parent_id FROM your_table WHERE parent_id = your_target_parent_id UNION ALL -- 递归查询:选择子节点 SELECT t.id, t.parent_id FROM your_table t INNER JOIN child_tree ct ON t.parent_id = ct.id ) SELECT * FROM ch...
WITH recursive 表名 AS ( 初始语句(非递归部分) UNION ALL 递归部分语句 ) [ SELECT| INSERT | UPDATE | DELETE] 数据准备 代码语言:javascript 代码运行次数:0 运行 AI代码解释 -- --- -- Table structure for tree -- --- DROP TABLE IF EXISTS `tree`; CREATE TABLE `tree` ( `id` int NOT N...
If I run a SELECT `hierarchyid` WHERE `parentid`=`hierarchyid` I would get the first level of children but I'm not sure how to make that cascade down the levels. Thanks everyone, Cheers Nic Subject Written By Posted Recursive query ...
selectGROUP_CONCAT(Id)intotempidsfromdudeptwhereFIND_IN_SET(ParentId,tempids)>0; endwhile; -- select ids; returnids; end; $$ delimiter ; selectgetChildListId(4); select*fromdudeptwhereFIND_IN_SET(Id,getChildListId(4)); -- 手动实现递归查询(向上递归) ...
We assume we have a table of people with a parent-child relationship: CREATE TABLE tree (person CHAR(20), parent CHAR(20)); INSERT INTO tree VALUES ('Robert I', NULL), ('Thurimbert', 'Robert I'), ('Robert II', 'Thu...
The order of rows is from child to parent; if the opposite order is desired, add a depth and order by it:WITH RECURSIVE cte AS ( SELECT name, parent, 0 as depth FROM category WHERE name='FLASH' UNION ALL SELECT c.name, c.parent, cte.depth-1 FROM category c JOI...
Learning how to write recursive queries. I have the basics down and can get the desired results. What I need help with is writing a query using the table from the recursive query. Using this simple example WITH RECURSIVE YR_RNG (YR_RNG) AS ...