MySQL查询最后7天的数据

[huanyufeng]

本人新手，半路出家需要用到MySQL，查询最后７天的数据（不是最近）
数据表tablet123
数据：
CREATE TABLE `tablet123` (
`id` int(11) NOT NULL,
`date` varchar(20) DEFAULT NULL,
`name` varchar(20) DEFAULT NULL,
`description` varchar(200) DEFAULT NULL,
PRIMARY KEY (`id`)


请大神们帮忙看下，谢谢！

[huanyufeng]

引用 2 楼 zjcxc 的回复:

-- 最后日期-6 的 select * from tablet123 where cast(date as date) >=( select max(cast(date as date))-6 from tablet123 ) -- 最后 7 天有数据的 select * from tablet123 where cast(date as date) in ( select distinct cast(date as date) from tablet123 order by cast(date as date) desc limit 7)

谢谢兄弟！我的问题已经解决

[huanyufeng]

引用 2 楼 zjcxc 的回复:

-- 最后日期-6 的 select * from tablet123 where cast(date as date) >=( select max(cast(date as date))-6 from tablet123 ) -- 最后 7 天有数据的 select * from tablet123 where cast(date as date) in ( select distinct cast(date as date) from tablet123 order by cast(date as date) desc limit 7)

我的数据有9月份和10月份的 我尝试查询50天的数据，只能查到10月的，9月之前的查不出来，这个怎么处理？

[huanyufeng]

引用 4 楼 huanyufeng 的回复:

[quote=引用 2 楼 zjcxc 的回复:] -- 最后日期-6 的 select * from tablet123 where cast(date as date) >=( select max(cast(date as date))-6 from tablet123 ) -- 最后 7 天有数据的 select * from tablet123 where cast(date as date) in ( select distinct cast(date as date) from tablet123 order by cast(date as date) desc limit 7)

我的数据有9月份和10月份的 我尝试查询50天的数据，只能查到10月的，9月之前的查不出来，这个怎么处理？[/quote] 已经自己解决 select * from tablet123 where cast(date as date) >=(select date_sub(max(cast(date as date)), interval 60 day) from tablet123)

[zjcxc]

最后7天的定义是什么？ 最大的日期-6 到最大日期？ 还是最后有数据的7个日期？

[zjcxc]

-- 最后日期-6 的 select * from tablet123 where cast(date as date) >=( select max(cast(date as date))-6 from tablet123 ) -- 最后 7 天有数据的 select * from tablet123 where cast(date as date) in ( select distinct cast(date as date) from tablet123 order by cast(date as date) desc limit 7)