蜂巢中复杂结构的聚合

Question

我在 hive 中创建了一个 table，在一列中包含 complex structure。示例记录：

+-----------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+--+
| id        |                                                                                                                                                               order                                                                                                                                                                |  |
+-----------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+--+
|         1 | [{"books":"prince","order_timestamp":"2022-01-19 00:45:22","check_out_timestamp":"2022-01-19 00:45:22"},{"books":"venceremos","order_timestamp":"2022-01-19 00:47:13","check_out_timestamp":null},{"books":"rich dad poor dad","order_timestamp":null,"check_out_timestamp":"2022-01-19 00:47:13"}]                                |  |
|         2 | [{"books":"lord of flies","order_timestamp":"2022-01-11 12:47:14","check_out_timestamp":"2022-01-11 13:08:20"},{"books":"test","order_timestamp":"2022-01-11 12:47:14","check_out_timestamp":"2022-01-11 12:47:14"},{"books":"physics","order_timestamp":"2022-01-11 12:47:14","check_out_timestamp":"2022-01-11 12:47:14"}]       |  |
|         3 | [{"books":"test","order_timestamp":"2022-01-14 18:21:03","check_out_timestamp":"2022-01-14 18:21:03"},{"books":"up and down","order_timestamp":"2022-01-14 18:23:21","check_out_timestamp":"2022-01-14 18:23:21.018"},{"books":"mathematics","order_timestamp":"2022-01-14 18:23:21","check_out_timestamp":"2022-01-14 18:23:21"}] |  |
+-----------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+--+

我想问一下，如何在这个列中进行一些聚合？例如，22 年 1 月 14 日订购了多少本书或最畅销的书？

Answer 1

使用lateral view inline分解结构数组并计算。例如，每个日期订购了多少本书：

select date(e.order_timestamp) order_date 
       count(*)  as book_cnt
 from table_name
      lateral view inline(order) e as books, order_timestamp, check_out_timestamp
where date(e.order_timestamp) = date('2022-01-14')
group by date(e.order_timestamp)

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