Single line: --
Multiple lines: /* */
-- Query table
SELECT * FROM students
WHERE class = 5 -- <> means not equal
ORDER BY grade, age DESC
LIMIT 5 OFFSET 5;
-- Query table
SELECT * FROM students
WHERE class = 5
ORDER BY grade, age DESC;
-- Query table
SELECT class, AVG(grade) AS avg
FROM students
GROUP BY class
HAVING grade >= 80
ORDER BY avg DESC;
-- Select few columns (rename)
SELECT name AS 'Titles', grade AS 'Score'
FROM movies;
SELECT AVG(grade) FROM students;
-- AVG, SUM, MAX, MIN, COUNT, ROUND(<>,#)
-- calculate total rows
SELECT COUNT(*) FROM students;
-- ignore NULL
SELECT COUNT(grade) FROM students;
SELECT COUNT(DISTINCT class) FROM students;