SQL-仅获取每个记录的特定日期

Question

I have a table called form with the following fields

StudentID
form
date

Separately there is a student table containing their info, and StudentID is a foreign key from that table.

When a student moves form, a new entry is added for them in this table. That way we have a record of when they moved.

I'm trying to make a query that will get all the information from the student table (for every student), and join to it the form they are currently in (ie, the form with the most recent date from the form table above).

I can do it for individual students, but can't find a way to do it for the entire student table.

Any help would be greatly appreciated.

Answer 1

Here is one method:

select s.*,
       max(f.date) as MostRecentDate,
       substring_index(group_concat(form order by date desc), ',', 1) as MostRecentForm
from student s join
     form f
     on s.StudentID = f.StudentId
group by s.StudentId;