MariaDB 10.4

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CREATE TABLE table1(course VARCHAR(10), mark int, name varchar(10));
INSERT INTO table1 VALUES 
  ('Maths', 60, 'Thulile'),
  ('Maths', 60, 'Pritha'),
  ('Maths', 70, 'Voitto'),
  ('Maths', 55, 'Chun'),
  ('Biology', 60, 'Bilal'),
   ('Biology', 70, 'Roger');

Records: 6  Duplicates: 0  Warnings: 0


CREATE TABLE table2(id INT, limitvalue INT)
INSERT INTO table2 VALUES (1, 5)
WITH rownums AS (
  SELECT *,
         ROW_NUMBER() OVER () AS rn
  FROM table1
)
SELECT *
FROM rownums
WHERE rn <= (SELECT limitvalue FROM table2 WHERE id = 1)


course
mark
name
rn


Biology
60
Bilal
1

Biology
70
Roger
2

Maths
70
Voitto
3

Maths
55
Chun
4

Maths
60
Thulile
5


WITH rownums AS (
  SELECT *,
         ROW_NUMBER() OVER (ORDER BY mark DESC) AS rn
  FROM table1
)
SELECT *
FROM rownums
WHERE rn <= (SELECT limitvalue FROM table2 WHERE id = 1)


course
mark
name
rn


Biology
70
Roger
1

Maths
70
Voitto
2

Biology
60
Bilal
3

Maths
60
Thulile
4

Maths
60
Pritha
5

course	mark	name	rn
Biology	60	Bilal	1
Biology	70	Roger	2
Maths	70	Voitto	3
Maths	55	Chun	4
Maths	60	Thulile	5