用sql语句怎么把同一表按照列data1,data2,data3的最小的那个按时间从小到大排序？

[sheyu8]

a
ids data1 data2 data3
1 1010-1-1 1009-1-1
2 1012-1-1 2005-1-1
3 1014-1-1 1020-1-1 1000-1-1
4 1013-1-1 1003-1-1

显示结果应该为按照data1,data2,data3的最小的那个按时间从小到大排序，显示如下：
ids data1 data2 data3
3 1014-1-1 1020-1-1 1000-1-1
4 1013-1-1 1003-1-1
1 1010-1-1 1009-1-1
2 1012-1-1 2005-1-1

[shuiniu]

select * from a
order by data1 desc
--------------------------
????

[sunsunup]

select a.*, sort_data =
case when data1> data2 then
case when data1 > data3 then data1 else data1 end
else
case when data2 > data3 then data2 else data3 end
end
from a order by sort_data

[wolfpzp]

select a.*, sort_data =
case when data1<= data2 then
case when data1 <= data3 then data1 else data3 end
else
case when data2 <= data3 then data2 else data3 end
end
from a order by sort_data

[realgz]

来点长的，不过效率应该可以
select a.*
from a, (select ids,min(data) from (select ids,data1 data from a a3 data union all select ids,data2 data from a a4 union all select ids,data3 data from a a5) ax group by ids) a2
where a.ids=a2.ids
order by a2.data

[wolfpzp]

select A.*
FROM A LEFT JOIN (select A.ID, sort_data =
case when data1<= data2 then
case when data1 <= data3 then data1 else data3 end
else
case when data2 <= data3 then data2 else data3 end
end
from A ) B ON A.ID = B.ID
order by B.sort_data