Edward Gonzalez

[eddygonzalez9708]

Exercises, Day 1

1. Create a table called track that holds information about a music track. It should contain:

• An autoincrementing id
• A title (of type VARCHAR, probably)
• A reference to an id in table album (the album the track is on). This should be a foreign key.

2. Create a table called artist_album to connect artists to albums. (Note that an artist might have several albums and an album might be created by multiple artists.)

• Use foreign keys for this, as well.

3. Run the queries in the file setup.sql. This will populate the tables.

• Fix any errors at this point by making sure your tables are correct.
• DROP TABLE can be used to delete a table so you can recreate it with CREATE TABLE.

4. Write SQL SELECT queries that:

• Show all albums.
• Show all albums made between 1975 and 1990.
• Show all albums whose names start with Super D.
• Show all albums that have no release year.

5. Write SQL SELECT queries that:

• Show all track titles from Super Funky Album.
• Same query as above, but rename the column from title to Track_Title in the output.
• Select all album titles by Han Solo.
• Select the average year all albums were released.
• Select the average year all albums by Leia and the Ewoks were released.
• Select the number of artists.
• Select the number of tracks on Super Dubstep Album.

Exercises, Day 2

1. Create a database for taking notes.

• What are the columns that a note table needs?
• If you have a timestamp field, how do you auto-populate it with the date?
• A note should have a foreign key pointing to an author in an author table.
• What columns are needed for the author table?

2. Write queries that:

• Insert authors to the author table.

• Insert notes to the note table.

• Select all notes by an author's name.

• Select author for a particular note by note ID.

• Select the names of all the authors along with the number of notes they each have. (Hint: GROUP BY.)

• Delete authors from the author table.(Note that SQLite doesn't enforce foreign key constrains by default. You have to enable them by running PRAGMA foreign_keys = ON; before your queries.)

• What happens when you try to delete an author with an existing note?

• How can you prevent this?

• Submit a file notes.sql with the queries that build (CREATE TABLE/INSERT) and query the database as noted above.