Challenge_Gradebook.sql

CREATE TABLE student_grades (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    name TEXT,
    number_grade INTEGER,
    fraction_completed REAL);
    
INSERT INTO student_grades (name, number_grade, fraction_completed)
    VALUES ("Winston", 90, 0.805);
INSERT INTO student_grades (name, number_grade, fraction_completed)
    VALUES ("Winnefer", 95, 0.901);
INSERT INTO student_grades (name, number_grade, fraction_completed)
    VALUES ("Winsteen", 85, 0.906);
INSERT INTO student_grades (name, number_grade, fraction_completed)
    VALUES ("Wincifer", 66, 0.7054);
INSERT INTO student_grades (name, number_grade, fraction_completed)
    VALUES ("Winster", 76, 0.5013);
INSERT INTO student_grades (name, number_grade, fraction_completed)
    VALUES ("Winstonia", 82, 0.9045);
select name, number_grade, round(fraction_completed*100) as percent_completed from student_grades;

select count(*),
    case
        when number_grade>90 then 'A'
        when number_grade>80 then 'B'
        when number_grade>70 then 'C'
        else 'F'
        end as "letter_grade"
from student_grades group by letter_grade;