我似乎经常遇到这个问题,因为我的数据格式如下:
+----+----------------------+ | id | colors | +----+----------------------+ | 1 | Red,Green,Blue | | 2 | Orangered,Periwinkle | +----+----------------------+ 但我想要这样格式化:
+----+------------+ | id | colors | +----+------------+ | 1 | Red | | 1 | Green | | 1 | Blue | | 2 | Orangered | | 2 | Periwinkle | +----+------------+ 有什么好方法吗?这种操作甚至叫做什么?
我认为这是您需要的(存储过程):Mysql将列字符串拆分为行
DELIMITER $$
DROP PROCEDURE IF EXISTS explode_table $$ CREATE PROCEDURE explode_table(bound VARCHAR(255))
BEGIN
DECLARE id INT DEFAULT 0; DECLARE value TEXT; DECLARE occurance INT DEFAULT 0; DECLARE i INT DEFAULT 0; DECLARE splitted_value INT; DECLARE done INT DEFAULT 0; DECLARE cur1 CURSOR FOR SELECT table1.id, table1.value FROM table1 WHERE table1.value != ''; DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = 1;
DROP TEMPORARY TABLE IF EXISTS table2; CREATE TEMPORARY TABLE table2( id
INT NOT NULL, value
VARCHAR(255) NOT NULL ) ENGINE=Memory;
OPEN cur1; read_loop: LOOP FETCH cur1 INTO id, value; IF done THEN LEAVE read_loop; END IF;
SET occurance = (SELECT LENGTH(value)
- LENGTH(REPLACE(value, bound, ''))
+1);
SET i=1;
WHILE i <= occurance DO
SET splitted_value =
(SELECT REPLACE(SUBSTRING(SUBSTRING_INDEX(value, bound, i),
LENGTH(SUBSTRING_INDEX(value, bound, i - 1)) + 1), ',', ''));
INSERT INTO table2 VALUES (id, splitted_value);
SET i = i + 1;
END WHILE;
END LOOP;
SELECT * FROM table2; CLOSE cur1; END; $$来源:stack overflow
版权声明:本文内容由阿里云实名注册用户自发贡献,版权归原作者所有,阿里云开发者社区不拥有其著作权,亦不承担相应法律责任。具体规则请查看《阿里云开发者社区用户服务协议》和《阿里云开发者社区知识产权保护指引》。如果您发现本社区中有涉嫌抄袭的内容,填写侵权投诉表单进行举报,一经查实,本社区将立刻删除涉嫌侵权内容。