SQL Hive 根据列值添加列

Question

我有一个看起来像这样的查询

select
  number,
  class,
   unix_timestamp(date1) - unix_timestamp(date2) as time_example,
   sum(unix_timestamp(date1) - unix_timestamp(date2)) over(partition by unix_timestamp(date1) - unix_timestamp(date2) order by class) as class_time
from myTable

给出的结果如

number        class         time_example       class_time
1             math          5                  5
1             science       5                  10
1             art           5                  15
1             math          2                  2
1             science       2                  4
1             art           2                  6
1             math          10                 10
1             science       10                 20
1             art           10                 30

我想根据类添加列，并且只有 3 个不同的列，因为只有 3 个列。例如，数学的时间会得到 17。这是我想要得到的所需表格

number        class         class_time
1             math          17
1             science       17
1             art           17

Answer 1

你可以使用group by来做到这一点

select number, class,
sum(unix_timestamp(date1) - unix_timestamp(date2)) as class_time
from myTable
group by number,class;