UPPCL AE 2018:6

Question

 

Let $\text{E}1$ and $\text{E}2$ be two entities in an $\text{E/R}$ diagram with simple single-valued attributes. $\text{R}1$ and $\text{R}2$ are two relationships between $\text{E}1$ and $\text{E}2,$ where $\text{R}1$ is one-to-many and $\text{R}2$ is many-to-many. $\text{R}1$ and $\text{R}2$ do not have any attributes of their own. What is the minimum number of tables required to represent this situation in the relational model?

• A. $2$
• B. $4$
• C. $3$
• D. $5$

Answer 1

E1 -----R1/R2-------E2     

R1:Many to One

R2:Many to Many

Required Tables:

E1---->1 and E----->1 

R1 can be represented by adding foreign Key to may Sided Relation.

R2 require another table which will contain Primary Key of both E1 and E2

Hence in total 3 tables are required.