mysql 循环加条件语句

DELIMITER //
CREATE PROCEDURE traverse_tree(IN node_id INT)
BEGIN
    -- 处理当前节点
    SELECT * FROM your_table WHERE id = node_id;
    
    -- 递归遍历子节点
    DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;
    DECLARE child_id INT;
    DECLARE cur CURSOR FOR SELECT id FROM your_table WHERE parent_id = node_id;
    
    OPEN cur;
    
    read_loop: LOOP
        FETCH cur INTO child_id;
        IF done THEN
            LEAVE read_loop;
        END IF;
        CALL traverse_tree(child_id);
    END LOOP;
    
    CLOSE cur;
END //
DELIMITER ;

UPDATE your_table
SET status = CASE
    WHEN some_column = 'value1' THEN 'new_status1'
    WHEN some_column = 'value2' THEN 'new_status2'
    ELSE 'default_status'
END;