[英]SQL AWS Athena Group by Without a Column
I have this dataset我有这个数据集
patient_id doctor_id status created_at
1 1 A 2020-10-01 10:00:00
1 1 P 2020-10-01 10:30:00
1 1 U 2020-10-01 10:35:00
1 2 A 2020-10-01 10:40:00
...
I want to group it by patient_id and doctor_id but without the status is grouped so the result will be like this我想按patient_id和doctor_id对其进行分组,但没有对状态进行分组,因此结果将是这样的
patient_id doctor_id status created_at
1 1 U 2020-10-01 10:35:00
1 2 A 2020-10-01 10:40:00
...
AWS Athena have to grouped all column but I need the last status AWS Athena 必须对所有列进行分组,但我需要最后一个状态
In Athena/Presto you can do this with themax_by
function:在 Athena/Presto 中,您可以使用max_by
函数执行此max_by
:
SELECT
patient_id,
doctor_id,
MAX_BY(status, created_at) AS last_status
FROM the_table
GROUP BY 1, 2
max_by(x, y)
function returns the value of the column x
for the row with the max value of column y
of the group. max_by(x, y)
函数返回具有组中第y
列最大值的行的x
列的值。
ROW_NUMBER
provides one option here: ROW_NUMBER
在这里提供了一个选项:
WITH cte AS (
SELECT *,
ROW_NUMBER() OVER (PARTITION BY patient_id, doctor_id ORDER BY created_at DESC) rn
FROM yourTable
)
SELECT patient_id, doctor_id, status, created_at
FROM cte
WHERE rn = 1
ORDER BY patient_id, doctor_id;
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