I have this data in a MySQL table
+---------+--------+------------+---------------------+
| student | course | allocation | time_created |
+---------+--------+------------+---------------------+
| 1 | 1 | 0.2 | 2020-01-01 00:00:00 |
| 1 | 2 | 0.4 | 2020-01-01 00:00:00 |
| 1 | 3 | 0.6 | 2020-01-01 00:00:00 |
| 1 | 2 | 0.9 | 2021-01-01 00:00:00 |
+---------+--------+------------+---------------------+
The first three rows are added in 2020 and correspond to allocations of student 1 for the courses 1, 2, and 3. The fourth row is added in 2021 and updated the allocation for the course 2 to 0.9.
My question is how do I get the latest value of the allocation for each pair of (student, course).
(Latest = Latest time_created)
I tried to use a simple groupby but I can't get the maximum value of allocation for a set of (student, course)
