如何从具有两个日期的表中聚合每个日期的记录数？

Question

I have following table:

person	arrival	departure
John	01/01/2022	04/01/2022
Ana	03/01/2022	04/01/2022
Ronald	04/01/2022	NULL

And I should get something like:

date	new_arrived	new_departured
01/01/2022	1	0
03/01/2022	1	0
04/01/2022	1	2

Could anyone help me? Thank you in advance!

Answer 1

My idea would be:

with temp1 as(
SELECT arrival FROM original_table
WHERE arrival is not null
UNION ALL
SELECT departure FROM original_table
WHERE departure is not null)

SELECT temp1.arrival as date, 
(SELECT Count(arrival) FROM original_table WHERE arrival=date),
( SELECT Count(departure) FROM original_table WHERE departure=date)
FROM temp1
GROUP BY temp1.arrival;