delimiter //
create procedure p6()
begin 
    declare row_id int; -- 自定义变量1  
    declare row_num int; -- 自定义变量2 
    declare done INT DEFAULT FALSE;  -- 默认为false 表述循环未执行完
    declare temp int;
    
        -- 声明游标
    declare my_cursor CURSOR FOR select id,num from A;
    declare CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;
    
    -- 开始循环
    open my_cursor;
        xxoo: LOOP
            fetch my_cursor into row_id,row_num;
            if done then   --  需要自己判断是否循环结束
                leave xxoo; -- 结束循环
            END IF;
            set temp = row_id + row_num;
            insert into B(number) values(temp);
        end loop xxoo;
    close my_cursor;
    
end  //
delimter ;

delimiter //
create procedure p7(
    in tpl varchar(255),
    in arg int
)
begin 
    set @xo = arg;
    PREPARE prod FROM 'select * from student where sid > ?'; -- 1. 预检测某个东西 SQL语句合法性
    EXECUTE prod USING @xo; -- 2. SQL =格式化 tpl + arg 
    DEALLOCATE prepare prod; -- 3. 执行SQL语句
end  //
delimter ;

---------------------------
call p7("select * from tb where id > ?",9)