mysql 获取规定时间段内每一天的统计数据

按年统计

SELECT count(*), DATE_FORMAT(order_info.create_time, '%Y-%m-%d') AS count_by_date FROM order_info WHERE DATE_FORMAT(order_info.create_time, '%Y') = '2017' GROUP BY count_by_date ORDER BY NULL 

按月统计

SELECT count(*), DATE_FORMAT(order_info.create_time, '%Y-%m-%d') AS count_by_date FROM order_info WHERE DATE_FORMAT(order_info.create_time, '%Y-%m') = '2017-04' GROUP BY count_by_date ORDER BY NULL 

具体变换可以自己根据需求变更