Timothy Treadwell has a lot on his plate protecting the bears of the Katmai National Park in Alaska. Help him keep track of all of his bear friends using SQL.
- Use the
CREATE TABLE
command to create a new table with various data types - Use the
INSERT INTO
command to insert data (i.e. rows) into a database table - Use the
SELECT
command with various functions and modifiers to write queries
This lab might seem a bit different than what you've seen before. Take a look at the file structure:
├── Gemfile
├── README.md
├── bin
│ ├── environment.rb # requires bundler and files
│ ├── run.rb # instantiates the SQLRunner class in the below file
│ └── sql_runner.rb # holds a class that handles executing your .sql files
├── lib
│ ├── create.sql # where you create your schema
│ └── insert.sql # where you insert your data
│ └── seed.sql # data for in-memory database
│ └── sql_queries.rb # where you write your sql queries
└── spec # all the specs
├── create_spec.rb # this tests your create.sql file
├── insert_spec.rb # this tests your insert.sql file
├── select_spec.rb # this tests the queries you write in this file
└── spec_helper.rb
Let's briefly go over what is happening in the before
block that our tests will be using.
before do
@db = SQLite3::Database.new(':memory:')
@sql_runner = SQLRunner.new(@db)
@sql_runner.execute_create_file
end
Before each test two important things happen.
First a new in-memory database is created. Why do we do this? Let's say we run our tests and they add ten items to our database. If we did not use an in-memory store, those would be in there forever. This way our database gets thrown out after every running of the tests. You can learn more about in-memory databases here.
Next a new SqlRunner
class is created. The SqlRunner
class lives in your bin
directory and was created to help connect to the database.
Get the tests in spec/create_spec.rb
to pass. Your CREATE
statement should look something like this:
CREATE TABLE bears (
//columns here
);
Your columns should be the following types:
column | type |
---|---|
id | integer |
name | text |
age | integer |
gender | char(1)(The choices would be "M" or "F") |
color | text |
temperament | text |
alive | boolean |
Read about SQLite3 Datatypes to determine what your insert values are going to be. Be sure to pay attention to how booleans are expressed in SQLite3.
Get the tests in spec/insert_spec.rb
to pass. Input the following 8 bears (you can make up details about them):
- Mr. Chocolate
- Rowdy
- Tabitha
- Sergeant Brown
- Melissa
- Grinch
- Wendy
- unnamed (the bear that killed Tim didn't have a name; refer back to how to create a record that doesn't have one value)
Get the tests in spec/select_spec.rb
to pass. Note that for this section, the database will be seeded with external data from the lib/seed.sql
file so don't expect it to reflect the data you added above. Note: Since it's a Ruby file, write your queries as strings in the lib/sql_queries.rb
.
You may be expected to use SQL statements that you're not particularly familiar with. Make sure you use the resources and Google to find the right statements.
View SQL Bear Organizer on Learn.co and start learning to code for free.