Groups all the students in the same section in a given academic term

studentBySection.sql

/**
 * INVOLVED TABLES
 *
 * TABLE: students
 *   id
 *   user_id
 *   degree_id
 *   ...
 *
 * TABLE: degrees
 *   id
 *   code varchar
 *   name varchar
 *   major varchar
 *
 * TABLE: term_attendance
 *   id
 *   student_id (the one who attended)
 *   school_calendar_id (the semester/term attended)
 *   year_level int (by the time of attendance)
 *   section varchar (by the time of attendance)
 *
 * TABLE: school_calendar 
 * (the table of semesters/terms that have passed or is passing)
 *   id
 *   part_number int (show the term be a semester, 1 means first semester)
 *   date_start datetime
 *   date_end datetime
 *
 * [NOTE: No need to make another column to specify what
 *  type of term (e.g. "semestral", "trimestral", "quarterly")
 *  to determine the type, just calculate the difference 
 *  of date_start and date_end. Should it result to approximately 
 *  6 months, it is a semester]
 */

@exampleDegree = 'BSIT' --stands for BS in Info Tech

SELECT 
  year_level, 
  section, 
  COUNT(*) 
FROM students 
INNER JOIN term_attendance 
ON term_attendance.student_id = students.id 
WHERE student.degree_id = (SELECT id FROM degrees WHERE code = 'BSIT')
GROUP BY year_level, section, school_calendar_id