PostgreSQL Count

The PostgreSQL COUNT function returns the number of the rows in a select.

SELECT COUNT(*) FROM table_name;

SELECT COUNT(column_name) FROM table_name;

id	good_type	name	description	price
1	A	Car_1	Car 1 description	100
2	A	Car_2	Car 2 description	200
3	A	Car_3	Car 3 description	100
4	B	Boat_4	Boat 4 description	500
5	B	Boat_5	Boat 5 description	300
6	C	Train_1	Train 123 description	800

SELECT COUNT(*) 
FROM goods;

SELECT COUNT(price) 
FROM goods 
WHERE price > 200;

SELECT good_type, COUNT(price) n_count
FROM goods
GROUP BY good_type
HAVING count(good_type) > 1;

good_type	n_count
B	2
A	3