Hive：select 按别名并按列名排序

Question

当前查询无效：

select datetime as a
from coffee_chain
order by datetime;

有大神知道原因吗

Answer 1

使用

select datetime as a from coffee_chain order by a;

hive> create table coffee_chain (datetime int);
OK

hive> select datetime as a from coffee_chain order by datetime;

FAILED: SemanticException Line 0:-1 Invalid table alias or column reference 'datetime': (possible column names are: a)

hive> select datetime as a from coffee_chain order by a;
OK

Hive: select by alias and order by column name