MySql查询一天注册了多少人 然后是精确到每小时
``` select sum(user_registered) as"注册时间" ,count(*) as "注册人数" from wp_users group by date_format(user_registered, '%Y-%m-%d %H ')='2017-7-25' ``` 精确到每小时 ``` SELECT CURDATE() - INTERVAL 1 DAY AS '昨天', IFNULL(SUM(CASE HOUR(FROM_UNIXTIME(u...