MySQL中利用存储过程分割字符串的方法
现有一段字符串，如apple,banana,orange,pears,grape，要把它按照逗号(,)分割成：apple
banana
orange
pears
grape
然后使用where in()方法可以查询。
1、具体函数：
[*]# 函数：func_split_TotalLength
[*]DELIMITER $$
[*]DROP
function IF EXISTS `func_split_TotalLength` $$
[*]CREATE DEFINER=`root`@`%` 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` $$
[*]CREATE DEFINER=`root`@`%` FUNCTION `func_split`
[*](f_string varchar(1000),f_delimiter varchar(5),f_order int) RETURNS
varchar(255) CHARSET utf8
[*]BEGIN
[*] # 拆分传入的字符串，返回拆分后的新字符串
[*] declare result varchar(255) default
'';
[*] set result = reverse(substring_index(reverse(substring_index(f_string,f_delimiter,f_order)),f_delimiter,1));
[*] return result;
[*]END$$
[*]DELIMITER;
[*]# 存储过程：splitString
[*]DELIMITER $$
[*]DROP
PROCEDURE IF EXISTS `splitString` $$
[*]CREATE
PROCEDURE `splitString`
[*](IN f_string varchar(1000),IN f_delimiter varchar(5))
[*]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;
[*] insert
into tmp_split(`status`) values (func_split(f_string,f_delimiter,i));
[*]end while;
[*]END$$
[*]DELIMITER;
2、测试是否能成功分割
[*]call splitString("apple,banana,orange,pears,grape",",");
[*]select * from tmp_split;
运行结果如下，说明分割成功：
mysql> call splitString("apple,banana,orange,pears,grape",",");
select * from tmp_split;
Query OK, 1 row affected
+--------+
| status |
+--------+
| apple |
| banana |
| orange |
| pears |
| grape |
+--------+
5 rows in set
mysql>
3、应用where in()查询
[*]# 先传入字符串，分割后保存在临时表tmp_split中
[*]call splitString("apple,banana,orange,pears,grape",",");
[*]# 将查询的结果作为其他查询的条件来使用
[*]select * from fruit where
in(select * from tmp_split);
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