这个表是从excel导过来的，导致‘说明’字段分行，为什么我的这段sql不能实现数据合并，不报错，也一直运行不出来

Question

问题遇到的现象和发生背景

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我想要达到的结果

这个表是从excel导过来的，导致‘说明’字段分行，为什么我的这段sql不能实现数据合并，不报错，也一直运行不出来

CREATE DEFINER=`bdo`@`%` PROCEDURE `编码`()
BEGIN
DECLARE a int(10) default 7936; 
DECLARE b VARCHAR(255);
DECLARE c VARCHAR(255);
DECLARE d VARCHAR(255);
while a>0 DO 
if (select Sheet1_copy1.`编码` from Sheet1_copy1 where id=a) is NULL AND (select Sheet1_copy1.`品目名称` from Sheet1_copy1 where id=a) is NULL
THEN
SELECT Sheet1_copy1.`说明` into b
from Sheet1_copy1
WHERE  id = a;
select Sheet1_copy1.`说明` into c
from Sheet1_copy1
where id = a-1;
SET d =CONCAT(c,b);
update Sheet1_copy1
set Sheet1_copy1.`说明` = d
where id = a-1;
set a=a-1;
end if;
END WHILE; 
END

Answer 1

错误是这样的：

可以参照这个写，我验证过的：

CREATE DEFINER=`root`@`%` PROCEDURE `test_excel`()
BEGIN
    DECLARE isFlag INT DEFAULT TRUE;
    declare id int;
    declare code varchar(20);
    declare remark varchar(20);
    declare allRemark text;
    declare cur cursor for 
    select exel_a.id,exel_a.code,exel_a.remark from csdn_test.exel_a order by exel_a.id desc;
    DECLARE CONTINUE HANDLER FOR NOT FOUND SET isFlag = FALSE;
    open cur;
    getName: loop
    fetch cur into id,code,remark;
    if isFlag is FALSE then
        LEAVE getName;
    end if;
    if code is null then
        set allRemark=concat(remark,ifnull(allRemark,''));
    else 
        UPDATE exel_a 
SET 
    exel_a.remark = CONCAT(exel_a.remark, IFNULL(allRemark, ''))
WHERE
    exel_a.id = id;
        set allRemark=null;
    end if;
    end loop getName;
    close cur;
END