求一统计sql语句

[garfieldzf]

按照sign_date 不为空的进行升序排序（不为空的排在最前），sign_date为空按照issu_date升序排序

select * from (
select '2011-09-14' as sign_date,'2011-09-01' as issu_date
union
select '2011-09-10' as sign_date,'2011-09-05' as issu_date
union
select '2011-09-12' as sign_date,'2011-09-02' as issu_date
union
select '' as sign_date,'2011-09-04' as issu_date
union
select '' as sign_date,'2011-09-05' as issu_date
) a 
order by sign_date ,issu_date

目前的结果：
2011-09-04
2011-09-05
2011-09-10 2011-09-05
2011-09-12 2011-09-02
2011-09-14 2011-09-01
想要的结果:
2011-09-10 2011-09-04
2011-09-12 2011-09-05
2011-09-14 2011-09-05
2011-09-02
2011-09-01

[garfieldzf]

想要的结果：
2011-09-10 2011-09-04
2011-09-12 2011-09-05
2011-09-14 2011-09-05
2011-09-02
2011-09-01

[garfieldzf]

结果贴得时候有问题， 我想要的是回复的这个结果。

[迷茫的凡人]

来错板块了，你应该去SQL板块，那边高手多

[bdmh]

select * from (
select 1 as num,* from xxx where xxx is not null order by xxx
union
select 2 as num* from xxx where xxx is null order by xxx) order by num

仅供参考

[xfxlylove]

按你那样写基本不能实现，你可以用Case判断，如果为空的话你给他一个可能的最大日期。这样排序就没问题了

[风骑士之怒]

create table tt
(
sign_date nvarchar(20),
issu_date nvarchar(20)
)

insert into tt
select null,'2011-09-04' union all
select null,'2011-09-05' union all
select '2011-09-10','2011-09-05' union all
select '2011-09-12','2011-09-02' union all
select '2011-09-14','2011-09-01'


select * from (select top 10 * from tt where sign_date is not null order by sign_date) as a
union all
select * from (select top 10 * from tt where sign_date is null order by issu_date) as b

[风骑士之怒]

如果就单单一句SQL，还真不知道怎么弄，继续关注

[garfieldzf]

[Quote=引用 7 楼 wknight_it 的回复:]

如果就单单一句SQL，还真不知道怎么弄，继续关注
[/Quote]

感谢你的参与， 我是用别的方法解决的。

[风骑士之怒]

[Quote=引用 8 楼 lovesongforever 的回复:]
引用 7 楼 wknight_it 的回复:

如果就单单一句SQL，还真不知道怎么弄，继续关注


感谢你的参与， 我是用别的方法解决的。
[/Quote]
能分享下解决的办法吗？

[garfieldzf]

select case when sign_date='' then'NULL' else sign_date end sign_date,issu_date from (

select '2011-09-14' as sign_date,'2011-09-01' as issu_date

union

select '2011-09-10' as sign_date,'2011-09-05' as issu_date
union
select '2011-09-12' as sign_date,'2011-09-02' as issu_date
union
select '' as sign_date,'2011-09-04' as issu_date
union
select '' as sign_date,'2011-09-05' as issu_date

) a

order by sign_date ,issu_date