MYSQL 统计某时间段内每天的总数

统计一个月中，每天加入的会员总数

SELECT FROM_UNIXTIME(add_time, "%Y-%m-%e"), COUNT(*) AS count 
FROM member 
WHERE add_time BETWEEN UNIX_TIMESTAMP("2016-1-1 00:00:00") AND UNIX_TIMESTAMP("2016-1-31 00:00:00")
GROUP BY FROM_UNIXTIME(add_time, "%Y%m%e") 
ORDER BY add_time;