text: /*
  1112. Highest Grade For Each Student
  Table: Enrollments
  
  +---------------+---------+
  | Column Name   | Type    |
  +---------------+---------+
  | student_id    | int     |
  | course_id     | int     |
  | grade         | int     |
  +---------------+---------+
  (student_id, course_id) is the primary key of this table.
  
  Write a SQL query to find the highest grade with its corresponding course for each student. In case of a tie, you should find the course with the smallest course_id. The output must be sorted by increasing student_id.
  
  The query result format is in the following example:
  
  Enrollments table:
  +------------+-------------------+
  | student_id | course_id | grade |
  +------------+-----------+-------+
  | 2          | 2         | 95    |
  | 2          | 3         | 95    |
  | 1          | 1         | 90    |
  | 1          | 2         | 99    |
  | 3          | 1         | 80    |
  | 3          | 2         | 75    |
  | 3          | 3         | 82    |
  +------------+-----------+-------+
  
  Result table:
  +------------+-------------------+
  | student_id | course_id | grade |
  +------------+-----------+-------+
  | 1          | 2         | 99    |
  | 2          | 2         | 95    |
  | 3          | 3         | 82    |
  +------------+-----------+-------+
  */
  
  SELECT student_id, MIN(course_id) AS course_id, grade
  FROM Enrollments
  WHERE (student_id, grade) IN (
      SELECT student_id,MAX(grade) AS grade
      FROM Enrollments
      GROUP BY student_id
      )
  GROUP BY student_id
  ORDER BY student_id
  
  