mysql语句

分组查询：

1. 分组查询统计并且降序排序

SELECT count(1) as aa, reg_channel from cash_user group by reg_channel ORDER BY aa desc;

2.更改cash_user表中的reg_channel列值为'kaniu_meizu'的值为'meizu'

UPDATE cash_user set reg_channel='meizu' where reg_channel='kaniu_meizu';