the_report.sql

/*
Task:
You are given two tables: Students and Grades.
Students contains three columns ID, Name and Marks.
Grades contains the following data: Grade, Min_Marks, Max_Marks

Ketty gives Eve a task to generate a report containing three columns: Name, Grade and Mark. Ketty doesn't want the NAMES of those students who received a grade lower than 8.
The report must be in descending order by grade -- i.e. higher grades are entered first. If there is more than one student with the same grade (8-10) assigned to them, order those particular students by their name alphabetically.
Finally, if the grade is lower than 8, use "NULL" as their name and list them by their grades in descending order.
If there is more than one student with the same grade (1-7) assigned to them, order those particular students by their marks in ascending order.

Write a query to help Eve.
*/

SELECT
  CASE
    WHEN Grades.Grade < 8 THEN NULL
    WHEN Grades.Grade >= 8 THEN Students.Name
  END
  , -- using an alias for this CASE fails the task
  Grades.Grade,
  Students.Marks
FROM
  Students,
  Grades
WHERE
  Students.Marks BETWEEN Grades.Min_Mark
  AND Grades.Max_Mark
ORDER BY
  Grade DESC,
  Name