SQL Server 2022

By using db<>fiddle, you agree to license everything you submit by Creative Commons CC0.

CREATE TABLE students 
(
    student_id	INT,
    student_name	VARCHAR(512)
);

INSERT INTO students (student_id, student_name) VALUES
    ('69', 'Bart McEndree'),
	('77', 'Pepe LePew');

CREATE TABLE student_courses 
(
    student_id	INT,
    course_id	INT,
    percent_grade	FLOAT
);

INSERT INTO student_courses (student_id, course_id, percent_grade) VALUES
	('77', '101', '95.7'),
	('77', '202', '85.9'),
	('77', '303', '77.1'),
	('77', '404', '66.6'),
	('69', '303', '99.1'),  
	('69', '404', '96.9');

CREATE TABLE grades 
(
    from_percent	INT,
    to_percent	INT,
    letter_grade	VARCHAR(512),
    GPA	FLOAT
);

INSERT INTO grades (from_percent, to_percent, letter_grade, GPA) VALUES
	('0', '69', 'F', '0'),
	('70', '72', 'C-', '1.67'),
	('73', '76', 'C', '2.0'),
	('77', '79', 'C+', '2.33'),
	('80', '82', 'B-', '2.67'),
	('83', '86', 'B', '3.0'),
	('87', '89', 'B+', '3.33'),
	('90', '92', 'A-', '3.67'),
	('93', '96', 'A', '4.0'),
	('97', '100', 'A+', '4.0');

SELECT * FROM students
SELECT * FROM student_courses
SELECT * FROM grades

student_id	student_name
69	Bart McEndree
77	Pepe LePew

student_id	course_id	percent_grade
77	101	95.7
77	202	85.9
77	303	77.1
77	404	66.6
69	303	99.1
69	404	96.9

from_percent	to_percent	letter_grade	GPA
0	69	F	0
70	72	C-	1.67
73	76	C	2
77	79	C+	2.33
80	82	B-	2.67
83	86	B	3
87	89	B+	3.33
90	92	A-	3.67
93	96	A	4
97	100	A+	4

student_id	student_name	GPA
69	Bart McEndree	4
77	Pepe LePew	2.67