MySQL存储过程可以用于分割字符串,下面就为您详细介绍这种MySQL存储过程的用法,供您参考学习之用。
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
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>
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);
以上就是利用MySQL存储过程分割字符串的方法介绍。
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