How to structure a query with an intermediate table for the maximum course date?

To obtain the maximum course date using an intermediate table, you can apply an SQL query with aggregation and JOIN.

Suppose there are tables:

• courses (id, name)
• course_dates (course_id, date, price)

The task is to get a record with the maximum date for each course.

Example query:

SELECT c.id, c.name, cd.date, cd.price
FROM courses c
JOIN course_dates cd ON c.id = cd.course_id
JOIN (
    SELECT course_id, MAX(date) AS max_date
    FROM course_dates
    GROUP BY course_id
) max_dates ON cd.course_id = max_dates.course_id AND cd.date = max_dates.max_date;

Here:

• In the subquery max_dates, the maximum date is selected for each course.
• Then the main query joins courses with dates and filters by the maximum date.

This approach allows you to get the current data with the maximum course date using an intermediate table.