How to Identify Specific (Non-numeric) Sequence in SQL Server Records?

Question

Say I have a list of students and the time their attendance was taken in specific class types. How would I SELECT in SQL Server those students who attended a Math class directly followed by Science? Sample data as follows (adding spaces between students and sequencing by AttendanceDateTime for clarity):

Attendance for...

[Student]             [ClassAttended]     [AttendanceDateTime]
---------             ---------------     --------------------  
John                  Math                2018-07-01 08:04:58.277
John                  Science             2018-07-01 11:00:16.201
John                  Composition         2018-07-01 14:03:10.112

Edward                Math                2018-07-01 08:05:58.277
Edward                Composition         2018-07-01 11:01:16.201
Edward                Science             2018-07-01 14:02:10.112

Robert                Math                2018-07-01 08:03:58.277
Robert                Science             2018-07-01 11:02:16.201
Robert                Composition         2018-07-01 14:01:10.112

Allen                 Composition         2018-07-01 08:02:58.277
Allen                 Math                2018-07-01 11:03:16.201
Allen                 Science             2018-07-01 14:00:10.112

Results I am looking for:

[Student]           
---------           
John                
Robert              
Allen

I have looked at both How to find consecutive data in SQL and How to find consecutive rows based on the value of a column? for a while now and I think the idea is there but I'm not getting it. Any pointer in the right direction is much appreciated.

Answer 1

One way to solve this is with the Lead() function in a subquery:

SELECT DISTINCT student
FROM
    (
        SELECT table.*, Lead(ClassAttended) OVER (PARTITION BY Student ORDER BY AttendanceDateTime) as next_class_attended 
        FROM table
     )sub
WHERE classAttended = 'Math' AND next_class_attended = 'Science'