SELECT
    CASE 
        WHEN g.grade < 8 THEN NULL 
        ELSE s.name 
    END AS name,
    g.grade,
    s.marks
FROM 
    students s
JOIN 
    grades g
ON 
    s.marks BETWEEN g.min_mark AND g.max_mark
ORDER BY 
    g.grade DESC,s.name asc,s.marks asc;