CREATE TABLE grades (name TEXT, grade INTEGER);

INSERT INTO grades (name, grade) VALUES
    ("John", 97), ("Eric", 88), ("Jessica", 98), ("Mike", 82), ("Jeff", NULL);

SELECT "total students", COUNT(name) FROM grades;
SELECT "total grades", COUNT(grade) FROM grades;
SELECT "sum of grades", SUM(grade) FROM grades;
SELECT "grade average", AVG(grade) FROM grades;
SELECT "lowest grade", MIN(grade) FROM grades;
SELECT "highest grade", MAX(grade) FROM grades;
SELECT "names", GROUP_CONCAT(name) FROM grades;