select a.Estimated_Arrival_Date_s from (
select estimated_arrival_date Estimated_Arrival_Date_s from Is_Issues_Plan_Detail)a
where Estimated_Arrival_Date_s='aa'

------解决方案--------------------
探讨


跟sql的执行顺序有关

SQL code
select a.Estimated_Arrival_Date_s from (
select estimated_arrival_date Estimated_Arrival_Date_s from Is_Issues_Plan_Detail)a
where Estimated_Arrival_Date_s='aa'


------解决方案--------------------
UP一个。这地方都是sql高手，个人也标胶喜欢

------解决方案--------------------
SQL code

declare @T table (col varchar(1))
insert into @T
select 'a' union all
select 'b' union all
select 'c'

--order by 后面就可以用别名
select col a from @T order by a
--where后面用别名的话就需要嵌套一层
select col a from @T where a='b'
/*
Invalid column name 'a'.
*/