mysql查询列转成字符串group_concat
1、登录mysql,在test数据库中建裹言蕉立一个表:
CREATE TABLE `shoufei` ( `id` int(11) NOT NULL AUTO_INCREMENT, `shijian` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP, `xiangmu` varchar(20) NOT NULL, `jiage` float NOT NULL, `shuliang` int(11) NOT NULL, `jine` float DEFAULT NULL, PRIMARY KEY (`id`)) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=utf8

2、在表shoufei增加数据:

3、在表中,查询xiangmu字段,在查询结果组成一个字符串:
SELECT GROUP_CONCAT(xiangmu) FROM shoufei;

4、在查询项目组成的字符串时,定义间隔符号(-):
SELECT GROUP_CONCAT(xiangmu SEPARATOR '哄没-') FROM shoufei;

5、把诉雁字符串的字段的值升序排序(asc ,desc):
SELECT GROUP_CONCAT(xiangmu ORDER BY xiangmu ASC SEPARATOR '-') FROM shoufei;

6、在表中,把shuliang字段组成一个字符串:
SELECT GROUP_CONCAT(shuliang) FROM shoufei;

7、在数量组成的字符串有重复的值,把重复的值过滤:
SELECT GROUP_CONCAT(DISTINCT shuliang) FROM shoufei;
