# Advanced Finding Lab

## Objectives

1. Create a table using ActiveRecord.
2. Use Active Record's querying methods.

## Overview

In this lab, we'll be working in a TV show domain. We have a TV show model, the `Show` class, and a `shows` table that you'll create in your database.

You'll be required not only to write a migration that creates a `shows` table and gives the `Show` class certain attributes, but also to use Active Record's querying methods.

### Active Record Querying Methods

Active Record makes it easy to ask our database for certain information and datasets by providing a bunch of built-in methods for us. For example, we can request the sum of all of the values of a particular column with the `#sum` method:

```
<class name>.sum(:<column_name>)
```

We can query our database based on certain conditions using the `#where` method.

Let's say we have a `Song` class and table and each song has a `number_of_stars` rating attribute. We could query for songs with more than 3 stars like this:

```
Song.where("number_of_stars > ?", 3)
```

Let's look at one more example: Let's say we want to query our database for the lowest value in the `number_of_stars` column, i.e., the lowest rating that any song has:

```
Song.minimum(:number_of_stars)
```

You'll be writing methods that *rely on Active Record methods like `#minimum`, `#sum`, and `#where`* to get these tests passing.

Use the following resources to help you find the Active Record query methods that will help you pass these tests:

* [Calculations](http://guides.rubyonrails.org/active_record_querying.html#calculations)
* [Ordering](http://guides.rubyonrails.org/active_record_querying.html#ordering)
* [Conditions](http://guides.rubyonrails.org/active_record_querying.html#conditions)

## Instructions

### Migration

* Run `mkdir db` and then `mkdir db/migrate` to create the `migrate` folder within `db`. Then create a file in the `db/migrate` folder called `001_create_shows.rb`. In this file, write the migration code to create a `shows` table. The table should have `name`, `network`, `day`, and `rating` columns. `name`, `network`, and `day` have a datatype of string, and `rating` has a datatype of integer.
* Create an `app` folder with a `models` folder within it, and then create a file, `show.rb`, in `app/models`. In this file, you will define a `Show` class that inherits from `ActiveRecord::Base`.
* Now we need to create a second migration to add another column to our `shows` table. In the `db/migrate` folder, create another file, `002_add_season_to_shows.rb`, and write a migration to add a column, `season`, to the `shows` table. The datatype of this column is string.

**Note**: This lab is using ActiveRecord 5.2. You will need to specify this version in your migrations by having your classes inherit from `ActiveRecord::Migration[5.2]`.

### Methods

You'll be defining the following methods:

* `highest_rating`: this method should return the highest value in the ratings column. *hint*: if there is a `minimum` Active Record method, might there be a `maximum` method?
* `most_popular_show`: this method should return the show with the highest rating. *hint*: use the `highest_rating` method as a helper method.
* `lowest_rating`: returns the lowest value in the ratings column.
* `least_popular_show`: returns the show with the lowest rating.
* `ratings_sum`: returns the sum of all of the ratings.
* `popular_shows`: returns an array of all of the shows that have a rating greater than `5`. *hint*: use the `where` Active Record method.
* `shows_by_alphabetical_order`: returns an array of all of the shows sorted by alphabetical order according to their names. *hint*: use the `order` Active Record method.

View [Advanced Finding Lab](https://github.com/learn-co-curriculum/activerecord-tvshow) on Learn.co and start learning to code for free.