MySQL字符分割并存储到临时表中

CREATE DEFINER=`root`@`localhost` PROCEDURE `split`(in _string varchar(300))
BEGIN
# 求分割符号','的位置
declare _index int;

#使用临时表存储分割后的结果
drop temporary table if exists tmp_strs;
create temporary table tmp_strs(
str int(10) unsigned
);

set _index = locate(',',_string);
while _index > 0
do
insert into tmp_strs values(left(_string,_index-1));#将子字符串存入临时表
set _string =substr(_string from _index+1);
set _index = locate(',',_string);
end while;

if length(_string) >= 0 then
insert into tmp_strs values(_string);
end if;

END