Aggregate function

We cannot select other column that is not in group by or aggregate function.

AVG

SELECT AVG(column_name) FROM table_name

MAX

SELECT MAX(column_name) FROM table_name

MIN

SELECT MIN(column_name) FROM table_name

SUM

SELECT SUM(column_name) FROM table_name

COUNT

SELECT COUNT(DISTINCT column_name) FROM table_name

GROUP BY & ORDER BY & HAVING

SELECT column_name(s) FROM table_name
WHERE condition
GROUP BY column_name(s)
HAVING condition
ORDER BY column_name(s) DESC | ASC