diff --git a/lab-2/music-store-app/sql/dummy_data.sql b/lab-2/music-store-app/sql/dummy_data.sql
index 5db6038f8f89a35887340919cbac1bbb45743352..2bc338f8ffc9860a3690d71710e06c38e713c849 100644
--- a/lab-2/music-store-app/sql/dummy_data.sql
+++ b/lab-2/music-store-app/sql/dummy_data.sql
@@ -24,20 +24,27 @@ VALUES
('John', 'Lennon', 3),
('Madonna', NULL, NULL);
-INSERT INTO Album (name, year, artist_id, price)
+INSERT INTO Album (upc, title, year, artist_id, price, genre_id)
VALUES
-('Soul Rebel', 1970, 1, 25.99 ),
-('Catch A Fire', 1973, 1, 25.99 ),
-('Natty Dread', 1974, 1, 20.99 ),
-('Babylon By Bus', 1978, 1, 24.99 ),
-('Night Nurse', 1982, 5, 17.99 ),
-('Mr Issacs', 1982, 5, 9.99 ),
-('Black and Dekker', 1980, 6, 19.99 ),
-('Sunday Coming', 1970, 4, 15.99 );
+('123425364732', 'Soul Rebel', 1970, 1, 25.99, 1 ),
+('017263547261', 'Catch A Fire', 1973, 1, 25.99, 1 ),
+('018263526272', 'Natty Dread', 1974, 1, 20.99, 1 ),
+('018273527273', 'Babylon By Bus', 1978, 1, 24.99, 1 ),
+('491827364626', 'Night Nurse', 1982, 5, 17.99, 1 ),
+('018276272828', 'Mr Issacs', 1982, 5, 9.99, 1 ),
+('018273662728', 'Black and Dekker', 1980, 6, 19.99, 1 ),
+('726517237627', 'Sunday Coming', 1970, 4, 15.99, 1 ),
+('018274372722', 'Imagine', 1971, 7, 11.99, 6 ),
+('018273727287', 'Like a Virgin', 1984, 8, 9.99, 6 );
-INSERT INTO Track (title, album_id, track_number)
+INSERT INTO Track (name, album_upc, track_number)
VALUES
-('Sunday Coming', 8, 1),
-('These Eyes', 8, 2),
-('Hurting Me', 8, 3);
+('Sunday Coming', '726517237627', 1),
+('Imagine', '018274372722', 1),
+('Material Girl', '018273727287', 1),
+('Angel', '018273727287', 2),
+('Like a Virgin', '018273727287', 3),
+('Crippled Inside', '018274372722', 2),
+('These Eyes', '726517237627', 2),
+('Hurting Me', '726517237627', 3);
diff --git a/lab-2/music-store-app/sql/practice_queries.sql b/lab-2/music-store-app/sql/practice_queries.sql
index f2872a19d3abe2771b92fec648f3ac2ba3ea0680..1c05ab5a5b82d3321ed29798dc520079ee02b74e 100644
--- a/lab-2/music-store-app/sql/practice_queries.sql
+++ b/lab-2/music-store-app/sql/practice_queries.sql
@@ -13,4 +13,35 @@ SELECT name, year FROM Album WHERE price > 15;
UPDATE Album SET price=21.99 WHERE name='Soul Rebel';
/* Delete artists with first_name Madonna (Yay!) */
-DELETE FROM Artist WHERE first_name='Madonna';
\ No newline at end of file
+DELETE FROM Artist WHERE first_name='Madonna';
+
+/* Example simple table join.
+Gets title, price and year of albums
+where Artist last name is 'Marley'
+and orders by year ascending */
+SELECT title, price, year FROM Album
+INNER JOIN Artist
+ ON Artist.id=Album.artist_id
+WHERE Artist.last_name='Marley'
+ORDER BY year ASC;
+
+/* Example multi table join
+Gets track names, track numbers
+and titles of all pop albums */
+SELECT t.name, t.track_number, a.title
+FROM Track t
+INNER JOIN Album a
+ ON a.upc=t.album_upc
+INNER JOIN Genre g
+ ON g.id=a.genre_id
+WHERE g.name='Pop';
+
+/* Example multi table join
+Gets album title, genre and name
+of first track on every album */
+SELECT a.title, g.name, t.name FROM Album a
+INNER JOIN Genre g
+ ON a.genre_id=g.id
+INNER JOIN Track t
+ ON a.upc=t.album_upc
+WHERE t.track_number=1;
diff --git a/lab-2/music-store-app/sql/schema.sql b/lab-2/music-store-app/sql/schema.sql
index 3b2bb7725c5f648441cf92fb2dd6b8dcd7507838..8e1df6cfc50d37c27b438d50379bd5ee083ed2ec 100644
--- a/lab-2/music-store-app/sql/schema.sql
+++ b/lab-2/music-store-app/sql/schema.sql
@@ -9,7 +9,9 @@ CREATE TABLE Genre (
PRIMARY KEY (id)
);
-/* Define table for storing act (i.e. a group or solo artist) */
+/* Define table for storing act (i.e. a group or solo artist)
+ON DELETE CASCADE not needed in this
+case as a Band does not HAVE to have an associated genre */
CREATE TABLE Band (
id INT AUTO_INCREMENT,
name VARCHAR(50) NOT NULL,
@@ -32,27 +34,38 @@ CREATE TABLE Artist (
/* Define table for storing albums */
CREATE TABLE Album (
- id INT AUTO_INCREMENT,
- name VARCHAR(50) NOT NULL,
+ upc CHAR(12),
+ title VARCHAR(50) NOT NULL,
year YEAR(4),
artist_id INT,
compilation BOOLEAN NOT NULL DEFAULT 0,
price DECIMAL(5, 2) unsigned NOT NULL,
- PRIMARY KEY (id),
+ genre_id INT,
+ PRIMARY KEY (upc),
FOREIGN KEY (artist_id)
- REFERENCES Artist (id)
+ REFERENCES Artist (id),
+ FOREIGN KEY (genre_id)
+ REFERENCES Genre (id)
);
-/* Define table for storing single tracks */
+/* Define table for storing single tracks
+ON DELETE CASCADE will ensure no track
+is left that isn't linked to an album.
+ON UPDATE CASCADE will inherit any changes
+to the Album UPC (Universal Product Code).
+A composite PRIMARY KEY is used here to
+ensure the track_number is unique
+on any given album */
CREATE TABLE Track (
- id INT AUTO_INCREMENT,
- title VARCHAR(50) NOT NULL,
- album_id INT NOT NULL,
- track_number INT UNIQUE,
- PRIMARY KEY (id),
- FOREIGN KEY (album_id)
- REFERENCES Album (id)
+ name VARCHAR(50) NOT NULL,
+ album_upc CHAR(12) NOT NULL,
+ track_number INT,
+ PRIMARY KEY (album_upc, track_number),
+ FOREIGN KEY (album_upc)
+ REFERENCES Album (upc)
+ ON UPDATE CASCADE
+ ON DELETE CASCADE
);
/* Define table for storing customers */
@@ -77,17 +90,20 @@ CREATE TABLE Transaction (
PRIMARY KEY (id),
FOREIGN KEY (customer_id)
REFERENCES Customer(id)
+ ON DELETE CASCADE
);
/* Define table for storing line items */
CREATE TABLE LineItem (
id INT AUTO_INCREMENT,
trans_id INT NOT NULL,
- album_id INT NOT NULL,
+ album_upc CHAR(12) NOT NULL,
quantity INT NOT NULL DEFAULT 1,
PRIMARY KEY (id),
FOREIGN KEY (trans_id)
- REFERENCES Transaction (id),
- FOREIGN KEY (album_id)
- REFERENCES Album (id)
+ REFERENCES Transaction (id)
+ ON DELETE CASCADE,
+ FOREIGN KEY (album_upc)
+ REFERENCES Album (upc)
+ ON DELETE CASCADE
);