Levelup

🕵️‍♀️ Task

Calculate the highest duration from the movies table

movies

id (integer)
title (string)
year (integer)
duration (integer)
description (text)
image (string)
director_id (integer)

directors

id (integer)
name (string)
dob (date)
bio (text)
image (string)

actors

id (integer)
name (string)
dob (date)
bio (text)
image (string)

characters

id (integer)
actor_id (integer)
movie_id (integer)
name (string)

📖Method

You can calculate the largest/latest value in a particular column within a collection with .maximum. It returns a single value (of whatever datatype the column is).

Calculates the maximum value on a given column. The value is returned with the same data type of the column, or nil if there’s no row. See calculate for examples with options.

Data

id	title	year	duration	description	image	director_id

Data

id	name	dob	bio	image

Data

id	name	dob	bio	image
52	Uma Thurman	1970-04-29	Uma Karuna Thurman, daughte...	http://ia.media-imdb.com/im...
53	Duane Whitaker	1959-06-23	Duane Whitaker, a native of...	http://ia.media-imdb.com/im...
54	Paul Calderon			http://ia.media-imdb.com/im...
55	Frank Whaley	1963-07-20	Frank Whaley is a criticall...	http://ia.media-imdb.com/im...
56	Eli Wallach	1915-12-07	One of Hollywood's finest c...	http://ia.media-imdb.com/im...
57	Clint Eastwood	1930-05-31	Perhaps the icon of macho m...	http://ia.media-imdb.com/im...
315	Lionel Stander	1908-01-11	Lionel Stander, the movie c...	http://ia.media-imdb.com/im...
58	Lee Van Cleef	1925-01-09	One of the great movie vill...	http://ia.media-imdb.com/im...

Data

id	actor_id	movie_id	name
57	52	4	Mia Wallace
58	53	4	Maynard
59	54	4	Paul / English Bob
60	55	4	Brett
61	56	5	Tuco
62	57	5	Blondie
63	58	5	Sentenza / Angel Eyes
64	59	5	Alcoholic Union Captain (as...

Examples

Calculate the highest age for all users

User.all.maximum(:age)
=> 53

Calculate the highest price for all dishes

Dish.all.maximum(:price)
=> 21