ITPEC IP April 2026 Question 28

Question

When conditions (i) through (iv) are all fulfilled, which of the following is the E-R diagram that indicates the relationship between publishing companies, authors, and books? Here, the notation for the E-R diagram is as below.

[Notation]

[Figure: Box A joined by a line to box B, with an arrowhead at box B (A → B).]

This indicates that A and B have a one-to-many relationship.

[Conditions]
(i) A publishing company has contracts with multiple authors.
(ii) An author has a contract with only one (1) publishing company.
(iii) An author writes multiple books.
(iv) One (1) book is written by one (1) author.

Accepted Answer

a) [Figure: E-R diagram of three boxes in a row, Publishing Company, Author and Book. Publishing Company → Author → Book: the arrow from Publishing Company points to Author, and the arrow from Author points to Book.]

Answer

b) [Figure: E-R diagram of three boxes in a row, Publishing Company, Author and Book. Publishing Company → Author ← Book: the arrow from Publishing Company points to Author, and the arrow from Book points to Author.]

Answer

c) [Figure: E-R diagram of three boxes in a row, Publishing Company, Author and Book. Publishing Company ← Author → Book: the arrow from Author points to Publishing Company, and the arrow from Author points to Book.]

Answer

d) [Figure: E-R diagram of three boxes in a row, Publishing Company, Author and Book. Publishing Company ← Author ← Book: the arrow from Author points to Publishing Company, and the arrow from Book points to Author.]

Explanation