🕵️♀️ Task
You can calculate the sum of values in a particular column within a collection with .sum. It returns a single value (Integer or Float).
LevelUp
0.0% complete
LevelUp
0.0% complete
| id | title | year | duration | description | image | director_id |
|---|
| id | name | dob | bio | image |
|---|
| id | name | dob | bio | image |
|---|---|---|---|---|
| 573 | Ruth Warrick | 1915-06-29 | Reedy and regal actress Rut... | http://ia.media-imdb.com/im... |
| 574 | Ray Collins | 1889-12-10 | Ray Bidwell Collins was an ... | http://ia.media-imdb.com/im... |
| 575 | Erskine Sanford | 1885-11-19 | ||
| 576 | Everett Sloane | 1909-10-01 | Everett Sloane, the actor m... | http://ia.media-imdb.com/im... |
| 577 | William Alland | 1916-03-04 | Born in Delmar, Delaware, W... | |
| 578 | Paul Stewart | 1908-03-13 | Esteemed character actor Pa... | http://ia.media-imdb.com/im... |
| 586 | Shelley Duvall | 1949-07-07 | Shelley Alexis Duvall was b... | http://ia.media-imdb.com/im... |
| 587 | Danny Lloyd | 1973-01-01 | Danny Lloyd was selected fo... |
| id | actor_id | movie_id | name |
|---|---|---|---|
| 585 | 526 | 41 | Aogaeru, Assistant Manager ... |
| 586 | 527 | 41 | Kawa no Kami (voice) |
| 587 | 528 | 41 | Chihiro / Sen (voice) |
| 588 | 492 | 42 | A Factory Worker (as Charli... |
| 589 | 529 | 42 | A Gamin |
| 590 | 530 | 42 | Cafe Proprietor |
| 591 | 531 | 42 | Big Bill (as Stanley Sandford) |
| 592 | 532 | 42 | Mechanic |
Calculate the sum of ages for all users
User.all.sum(:age)
=> 4566
Calculate the sum of prices for all dishes
Dish.all.sum(:price)
=> 232