instruction.txt

Instructions
For this project, you need to log in to PostgreSQL with psql to create your database. Do that by entering psql --username=freecodecamp --dbname=postgres in the terminal. Make all the tests below pass to complete the project. Be sure to get creative, and have fun!
Don't forget to connect to your database after you create it 😄
Here's some ideas for other column and table names: description, has_life, is_spherical, age_in_millions_of_years, planet_types, galaxy_types, distance_from_earth.

Notes:
If you leave your virtual machine, your database may not be saved. You can make a dump of it by entering pg_dump -cC --inserts -U freecodecamp universe > universe.sql in a bash terminal (not the psql one). It will save the commands to rebuild your database in universe.sql. The file will be located where the command was entered. If it's anything inside the project folder, the file will be saved in the VM. You can rebuild the database by entering psql -U postgres < universe.sql in a terminal where the .sql file is.
If you are saving your progress on freeCodeCamp.org, after getting all the tests to pass, follow the instructions above to save a dump of your database. Save the universe.sql file in a public repository and submit the URL to it on freeCodeCamp.org.
Complete the tasks below
You should create a database named universe
Be sure to connect to your database with \c universe. Then, you should add tables named galaxy, star, planet, and moon
Each table should have a primary key
Each primary key should automatically increment
Each table should have a name column
You should use the INT data type for at least two columns that are not a primary or foreign key
You should use the NUMERIC data type at least once
You should use the TEXT data type at least once
You should use the BOOLEAN data type on at least two columns
Each "star" should have a foreign key that references one of the rows in galaxy
Each "planet" should have a foreign key that references one of the rows in star
Each "moon" should have a foreign key that references one of the rows in planet
Your database should have at least five tables
Each table should have at least three rows
The galaxy and star tables should each have at least six rows
The planet table should have at least 12 rows
The moon table should have at least 20 rows
Each table should have at least three columns
The galaxy, star, planet, and moon tables should each have at least five columns
At least two columns per table should not accept NULL values
At least one column from each table should be required to be UNIQUE
All columns named name should be of type VARCHAR
Each primary key column should follow the naming convention table_name_id. For example, the moon table should have a primary key column named moon_id
Each foreign key column should have the same name as the column it is referencing