hive执行报错：Both left and right aliases encountered in JOIN 'orderdate'

错误原因：两个表join的时候，不支持两个表的字段的 非相等 操作。

解决办法：
1、把不相等条件拿到where语句中

select ... from
class_order t1
left join class_order_refund t2 on t1.orderdate>t2.orderdate

可以改写成

select ... from
class_order t1
left join class_order_refund t2
where t1.orderdate>t2.orderdate

2、如果第一中方法不适用，可以在select字段中判断

select
...
if(t1.orderdate>t2.orderdate,0,1) as is_refund
...
from
class_order t1
left join class_order_refund t2 on t1.orderdate>t2.orderdate