mysql获取起始时间内的每一天日期

 第一种写法

select date_add('2019-07-11', interval (cast(help_topic_id as signed integer)) day) day
from mysql.help_topic
where help_topic_id < datediff('2019-07-31', '2019-07-11') + 1
order by help_topic_id;

第二种写法

SELECT @s :=@s + 1 as `index`, DATE(DATE_SUB('2019-07-31', INTERVAL @s DAY)) AS `date`
FROM mysql.help_topic,(SELECT @s := -1) temp
WHERE @s < datediff('2019-07-31', '2019-07-11')
ORDER BY `date`

第三种写法

select a.Date
from (
         select curdate() - INTERVAL (a.a + (10 * b.a) + (100 * c.a)) DAY as Date
         from (select 0 as a union all select 1 union all select 2 union all select 3 union all select 4 union all select 5 union all select 6 union all select 7 union all select 8 union all select 9) as a
                  cross join (select 0 as a union all select 1 union all select 2 union all select 3 union all select 4 union all select 5 union all select 6 union all select 7 union all select 8 union all select 9) as b
                  cross join (select 0 as a union all select 1 union all select 2 union all select 3 union all select 4 union all select 5 union all select 6 union all select 7 union all select 8 union all select 9) as c
     ) a
where a.Date between '2019-06-01' and '2019-06-30' order by a.Date asc

结果如下：

参考：mysql常用时间列表的查询——七天内、本月、本周、某天