How to GROUP multiple fields in MySQL GROUP

In SQL grouping, we all use GROUP BY. For a single one, we can directly GROUP BY XXX. But how do we operate multiple fields, I will share with you some tips.

In mysql statements, group by is easy to understand as group query.
For example, select sum (score) from user group by name indicates to query the total score of each person.
However, what about select sum (score) from user group by item and sex?
The following is the test result.

The test data is as follows:

The query result is as follows:

Result Analysis
The meaning of multiple fields in group by is that they are grouped by different combinations of each field.
In this example, item = math sex = 1 and item = math sex = 2 are allocated to different groups for calculation and purpose.