Question

我正在使用以下查询：

select UserId, Category from customer_data 
where (Category in ('Fashion','Electronics'))
and (Action in ('Click','AddToCart','Purchase'))
and customer_data.UserId not in (select ustomer_data.UserId from customer_data where customer_data.Category='Fashion' and customer_data.Category='Electronics')  ;

得到以下错误：

hive> Unsupported SubQuery Expression ''Fashion'': SubQuery expression refers to Outer query expressions only.

我不确定这个错误，我是否还需要为每个客户群使用表名，例如customer_data.Category，也可以在外部查询中使用？你能帮忙吗？

样本数据：

UserId,ProductId,Category,Action
1,111,Electronics,Browse
2,112,Fashion,Click
3,113,Kids,AddtoCart
4,114,Food,Purchase
5,115,Books,Logout
6,114,Food,Click
7,113,Kids,AddtoCart
8,115,Books,Purchase
9,111,Electronics,Click
10,112,Fashion,Purchase
3,112,Fashion,Click
12,113,Kids,AddtoCart

所需的输出：

Output File
•   userID
•   category

Answer 1

使用分析功能为每个UserId计算fashion_flag：

select UserId, Category
from
( --calculate User level flags
select UserId, Category,
       max(fashion_flag)     over (partition by UserId) as user_fashion_flag,
       max(electronics_flag) over (partition by UserId) as user_electronics_flag
from
(--maybe you do not need this subquery, if case will work inside max() over
    select UserId, Category,
           case when Category='Fashion'     then 1 else 0 end fashion_flag,
           case when Category='Electronics' then 1 else 0 end electronics_flag
      from customer_data 
     where (Category in ('Fashion','Electronics'))
       and (Action in ('Click','AddToCart','Purchase'))
) s

) s
where user_fashion_flag+user_electronics_flag=1 --not allow two flags at a time
;

不支持的子查询表达式“ Fashion”：子查询表达式仅引用外部查询表达式

1 个答案: