Question

this is a diagram to ans the following questions

odD-4748123 99 Page DVD title Has many DVD Copy N N Is sourced from rented to M Supplier Customer FIGURE 3.38 DVD store rental database (excluding purchase, supplier payment, rental payment and receipt Items)

Answer 1

Notations Understanding:

Rectangular box denotes an object/functionality which is in the scope

Daimond Box denotes to make a decision.

Literals used in the diagram

M - Many (ex - Many Supiers)

N - Number of (Ex- Number of DVD copies)

1 - 1 (ex- only 1 customer)

3.6) Explain where this diagram shows that a supplier can supply many DVD titles.

Sol: Figure 3.38 shows a suppliers can supply N number of DVD titles. It has M-N relation. That indicates supplier can supply N DVD titles. If you see in the SC below, There is a condition between supplier and DVD title.

That is to decide "is this DVD title sources from (valid) supplier or not. If so, It goes to next functionality called "DVD title"

Flow: Supplier -->Supply --> (N) DVD Titles

DVD title N Is sourced from M Supplier

3.7) Explain where this diagram shows that a DVD title can come from many suppliers.

Sol: in Figure 3.38 , On supplier rectangle , It has relatiion M. That indicated Many suppliers can supply. The immediate functionility is DVD titles .So Many suppliers can supply DVD titles.So flow Supplier (M)--> DVD Titles as per figure.

That fia

M Supplier

3.8) Explain where this diagram shows that a DVD title can have many DVD copies.

Sol: Figure 3.38 shows DVD title(1) has many DVD copies(N). N indicates DVD title can have many DVD copies.

Flow: DVD Title --> Has Many --> DVD Copies.

1 N DVD title Has many DVD copy

3.9) Explain where this diagram shows that a DVD copy relates to one title only.

Sol:  As highlighted below, 1 DVD title can have DVD copies. That indicated a DVD copy relates to one title only

Flow :Dvd Copy --> (1) DVD Title

1 N DVD title Has many DVD copy

3.10) Explain where this diagram shows that a DVD copy can be rented to one customer at a time.

Sol: Figure 3.38 says DVD copy and customer has N-1replation ship. That indicated DVD copy can be rented to one customer at a time.

This makeswWhen flow is DVD Copy(N) --> is Rented To --> 1 Customer.

Relation has been highlited in below SC.

DVD copy N Is rented to 1 Customer

3.11) Explain where this diagram shows that a customer can rent many copies of a DVD.

Sol:  This makes when flow is Customer(1) --> is Rented To --> Many DVD Copies(N). Please refer Figure 3.38 and above SC.