count-16.psql

-- The COUHT() function,

/**
* The COUNT function returns trhe numbe of input rows tht match a specific condition on a query.
* We can aplly COUNT on a specific column or all of them using the asterisk symbol.
*/

-- When using count, its pretty dull on itself since ir's just counrin the rows in a table.
-- Since every table is going to be the exact amount of rows, there is not a usecase to not use COUNT(*) when making a count of rows.
-- But COUNT() can be used with DISTINCT, to get the count of distinct rows in a column. Then we would pass in a specific column.

-- Let's plau around with the film table and rating,

-- Question: How many rows are in films?
SELECT COUNT(*) FROM film; -- The answer will be 1000

-- Quesiton: How many duplicate/distinct values in the rating column;
SELECT COUNT(DISTINCT(rating)) FROM film;