mysql recursive query, recursive delete stored procedure implementation

I wrote about the recursive query and deletion of oracle and mysql before, this time I will add a recursive implementation of mysql.

1. Implementation principle

(1) Delete the temporary table

(2) Create a temporary table and empty it

(3) Use a temporary table to store the id list recursively traversed

(4) Query the id list from the temporary table

2. Recursively query the stored procedure code

Stored procedure function name: findMenuChildList(menuPid varchar(32))

BEGIN
  DECLARE v_menu VARCHAR(32);
  DECLARE done INTEGER DEFAULT 0;
    -- 查询结果放入游标中,eguid原创
  DECLARE C_menu CURSOR FOR SELECT d.menuid
                           FROM vnmp_menu d
                           WHERE d.pid = menuPid;
  DECLARE CONTINUE HANDLER FOR NOT found SET done=1;
  SET @@max_sp_recursion_depth = 10;
    
    -- 传入的菜单id写入临时表,eguid原创
 INSERT INTO tmp_menu VALUES (menuPid);
  OPEN C_menu;
  FETCH C_menu INTO v_menu;
  WHILE (done=0)
  DO
        -- 递归调用，查找下级
    CALL findMenuChildList(v_menu);
    FETCH C_menu INTO v_menu;
  END WHILE;
  CLOSE C_menu;
END

3. Create a temporary table and get the data in the temporary table

Stored procedure function name: findMenuidArray(rootIds varchar(32))

BEGIN
    DROP TEMPORARY TABLE IF EXISTS tmp_menu;
    -- 创建临时表,eguid原创
    CREATE TEMPORARY TABLE tmp_menu(menuid VARCHAR(32));
    -- 清空临时表数据
    DELETE FROM tmp_menu;
    WHILE (done=0) 
    DO
        -- 循环调用递归函数,eguid原创
        CALL findMenuChildList(rootId);
    END WHILE;
    -- 删除父节点
    DELETE FROM tmp_menu where menuid=rootId;
    -- 从临时表查询结果
    SELECT menuid FROM tmp_menu;
END

4. Call the query stored procedure

CALL findMenuidArray('1');

Result (the query is a list of ids, which can facilitate related query and recursive deletion):

0fc126c5e60942229ae50ebbfb60e5fd
41ceae53abc14ab68a77dc527b1c0e5d
4334b8670a9244699d68fe4d80eeb4e9
5d3c6ab1793f4e55816a99ac71e4431b

5. Recursively delete stored procedure implementation code

Stored procedure function name: removeMenuById( rootId varchar(32))

BEGIN
    DROP TEMPORARY TABLE IF EXISTS tmp_menu;
    -- 创建临时表
    CREATE TEMPORARY TABLE tmp_menu(menuid VARCHAR(32));
    -- 清空临时表数据
    DELETE FROM tmp_menu;
    -- 发起调用
    CALL findMenuChildList(rootId);
    -- 不要删除父节点，删除时要同时删除父节点,eguid原创
    #DELETE FROM tmp_menu where menuid=rootId;
    -- 从临时表查询结果,eguid原创
    -- 删除菜单
    DELETE FROM vnmp_menu where menuid in(SELECT menuid FROM tmp_menu);
    -- 删除菜单关联表，如果设置了外键就不需要执行这步,eguid原创
    DELETE FROM vnmp_permission where associatedid in(SELECT menuid FROM tmp_menu);
END

4. Call the query stored procedure

CALL findMenuidArray('1');

result

update 4