Question

John has decided to organize his CD music collection. He wants to catalog his music by album, artist, songwriter, and song. An album is a compilation of songs, Songs are created when artists sing a song written by songwriters. John has noted that some songs appear multiple times in his catalog because they are on regular albums and compilation albums.

1. Write all the assumptions regarding the music catalog.
2. Based on your assumptions, construct a Crow’s Foot Notation Crow’s Foot Notation ERD diagram. Be sure to indicate the entities and the type of relationships between the entities.

Answer 1

Please find below the steps to obtain ERD for John’s album collection:

Step 1: List entities:

1. Album

2. Artist

3. SongWriter

4. Song

Step 2: Identify relationship among entities:

1. Album has at least one to many Songs and a Sing has many Albums, it is a many to many relationship

2. Song has at least one to many Artists and an artists sings many Songs

3. Song is written by one SongWriter but a SongWriter can write the many songs.

Step 3: Create ERD in Crow’s foot notation:

The above relationships and entities are shown in below ERD:

Step 4: ERD notations:

1. At least one to many cardinality notation:

2. Zero or many:

3. Exactly one: