Question

I have a table which looks like this

    courseid     session_date     title                 published
    1            2012-07-01       Training Course A     0
    1            2012-07-02       Training Course A     0
    2            2012-07-04       Training Course B     1
    2            2012-07-07       Training Course B     1
    3            2012-07-05       Training Course C     1
    3            2012-07-06       Training Course C     1
    4            2012-07-07       Training Course D     1
    4            2012-07-10       Training Course D     1

The table has two entries for each ID and Title because the session_date column shows the start date and the end date of the course.

I am trying to create a query that will pull the next five courses without showing any courses in the past.

I have gotten this far

    SELECT session_date, title, courseid
    FROM table
    WHERE published = 1 AND session_date > DATE(NOW())
    ORDER BY session_date ASC LIMIT 0,5

This pulls rows from the table for the next five session-dates but it includes both start dates and finish dates whereas I need the next five courses ordered by start date.

I need to create a query that will pull the earliest session_date for each courseid but ignore the row with the latest session_date for that same courseid but I am at a complete loss of how to do this.

Any help or advice would be most gratefully received.

Answer 1

If you group your results by course and select the MAX(session_date), you will get the latest of the dates associated with each course (i.e. the finish date):

SELECT   courseid, MIN(session_date) AS start_date
FROM     `table`
WHERE    published = 1
GROUP BY courseid
HAVING   start_date > CURRENT_DATE
ORDER BY start_date ASC
LIMIT    5

See it on sqlfiddle.