mysql字符串字段如何按照逗号截取进行储存

#查看已存在的存储过程：SHOW PROCEDURE STATUS

# 函数：func_split_TotalLength 
DELIMITER $$ 
DROP function IF EXISTS `func_split_TotalLength` $$ 
CREATE FUNCTION `func_split_TotalLength` 
(f_string varchar(1000),f_delimiter varchar(5)) RETURNS int(11) 
BEGIN

# 计算传入字符串的总length 
return 1+(length(f_string) - length(replace(f_string,f_delimiter,''))); 
END $$ 
DELIMITER;

# 函数：func_split 
DELIMITER $$ 
DROP function IF EXISTS `func_split` $$ 
CREATE FUNCTION `func_split` 
(f_string varchar(1000),f_delimiter varchar(5),f_order int) RETURNS varchar(255) CHARSET utf8 
BEGIN

 # 拆分传入的字符串，返回拆分后的新字符串 
declare result varchar(255) default ''; 
set result = reverse(substring_index(reverse(substring_index(f_string,f_delimiter,f_order)),f_delimiter,1)); 
return result; 
END$$ 
DELIMITER;

# 存储过程：splitString 
DELIMITER $$ 
DROP PROCEDURE IF EXISTS `splitString` $$ 
CREATE PROCEDURE `splitString` 
(IN f_string varchar(1000),IN f_delimiter varchar(10)) 
BEGIN

# 拆分结果 declare cnt int default 0; declare i int default 0; set cnt = func_split_TotalLength(f_string,f_delimiter); DROP TABLE IF EXISTS `tmp_split`; create temporary table `tmp_split` (`status` varchar(128) not null) DEFAULT CHARSET=utf8; while i < cnt do 
    set i = i + 1;

#插入除了'N'之外的所有数据
IF func_split(f_string,f_delimiter,i) != 'N' THEN
insert into tmp_split(`status`) values (func_split(f_string,f_delimiter,i)); END IF; 
end while; 
END$$ 
DELIMITER;

call splitString( (SELECT overdue_record_2year FROM Loan l WHERE l.papers_id = 231203199305030219 ORDER BY papers_id DESC LIMIT 1) ,","); 
select * from tmp_split;