DROP PROCEDURE IF EXISTS Cursor_Test;# MySQL returned an empty result set (i.e. zero rows).
DELIMITER $$
CREATE PROCEDURE Cursor_Test()
BEGIN
DECLARE Project_Number_val VARCHAR( 255 );
DECLARE Project_List_val VARCHAR(255);
DECLARE no_more_rows BOOLEAN;
DECLARE loop_cntr INT DEFAULT 0;
DECLARE num_rows INT DEFAULT 0;
DECLARE projects_cur CURSOR FOR
SELECT Project_Id
FROM Project_Details;
DECLARE CONTINUE HANDLER FOR NOT FOUND
SET no_more_rows = TRUE;
OPEN projects_cur;
select FOUND_ROWS() into num_rows;
the_loop: LOOP
FETCH projects_cur
INTO Project_Number_val;
IF no_more_rows THEN
CLOSE projects_cur;
LEAVE the_loop;
END IF;
SET Project_List_val=CONCAT(`Project_Number_val`,'_List')
-
> ---> **Please check am I doing CONCAT correct here?**
Insert Into test (Panel_Id) select Panel_Id from Project_List_val where Project_Number_val='9';
> --->**Is this taking 9_List as table name?**
SET loop_cntr = loop_cntr + 1;
END LOOP the_loop;
select num_rows, loop_cntr;
END $$# MySQL returned an empty result set (i.e. zero rows).
DELIMITER
有什么建议吗？ 大家好，
我在名为 Project_Number 的存储过程中有一个变量，它是 varchar 类型。
我的要求是“对于每个项目编号查询表 project_Number_List 从列表中获取结果并插入到其他表中”
比方说，Project_Number 可能是这样的 22,21,34,43,434 我需要查询的相应表是这样的 22_List, 21_List,34_List .....
我正在使用游标遍历 Project_Number，但我的问题是如何混合 project_number 和 _list，即 22_list 来查询表 22_List
最佳答案
试试这个:
SET Project_List_val=CONCAT(Project_Number_val,'_List')
关于mysql - CONCAT 在 mysql 存储过程中不起作用，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/14828172/