SQL 查询根据 ID 将多行合并为一行，同时将其他值保留在同一行中？

Question

首先，我已经搜索了一段时间了。

我有一个 table 看起来有点像这样 :

ID        Expenditure  MonthYear
1A        1,000        122019
1A        1,500        012020
1B        1,900        122019
1C        2,400        122019
1B        2,400        012020
1C        900          012020
1A        800          022020

由于行数可以达到几千行，有些ID重复了几十次，我想把不同ID的合并成一行，并添加保留其中所有信息的列。我想让 table 看起来像这样：

ID        Expenditure_1  MonthYear_1 Expenditure_2 MonthYear_2  Expenditure_3   MonthYear_3
1A        1,000          122019      1,500         012020       800             022020
1B        1,900          122019      2,400         012020       Null            Null
1C        2,400          122019      900           012020       Null            Null

在 Impala 上使用 SQL 解决此问题的最佳方法是什么？谢谢。

Answer 1

您可以使用条件聚合和 row_number():

select id,
       max(case when seqnum = 1 then expenditure end) as expenditure_1,
       max(case when seqnum = 1 then monthyear end) as monthyear_1,
       max(case when seqnum = 2 then expenditure end) as expenditure_2,
       max(case when seqnum = 2 then monthyear end) as monthyear_2,
       max(case when seqnum = 3 then expenditure end) as expenditure_3,
       max(case when seqnum = 3 then monthyear end) as monthyear_3
from (select t.*,
             row_number() over (partition by id order by right(monthyear, 4), left(monthyear, 2)) as seqnum
      from t
     ) t
group by id;

SQL 查询根据 ID 将多行合并为一行，同时将其他值保留在同一行中？

SQL Query to combine multiple rows into one based on ID while keeping other value in the same row?

sql

cloudera

impala