Database-Management-System
August 26, 2024ER-Model
August 26, 2024Database-Management-System
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Question 673
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Let M and N be two entities in an E-R diagram with simple single value attributes.
R 1 and R 2 are two relationship between M and N, where as
R 1 is one-to-many and R 2 is many-to-many.
The minimum number of tables required to represent M, N, R 1 and R 2 in the relational model are _______.
R 1 and R 2 are two relationship between M and N, where as
R 1 is one-to-many and R 2 is many-to-many.
The minimum number of tables required to represent M, N, R 1 and R 2 in the relational model are _______.
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4
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6
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7
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3
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Question 673 Explanation:
R 1 and R 2 two relationships between M and N
R 1 is one to many.
R 2 is many to many.
→ M and N have separate table because they need to store multiple values.
→ R 2 also have separate table by considering Primary keys M and N as foreign keys.
→ R 1 is converted to many side table i.e., N as Primary key and M as Foreign key.
So, totally we need 3 tables to store the value.
R 1 is one to many.
R 2 is many to many.
→ M and N have separate table because they need to store multiple values.
→ R 2 also have separate table by considering Primary keys M and N as foreign keys.
→ R 1 is converted to many side table i.e., N as Primary key and M as Foreign key.
So, totally we need 3 tables to store the value.
Correct Answer: D
Question 673 Explanation:
R 1 and R 2 two relationships between M and N
R 1 is one to many.
R 2 is many to many.
→ M and N have separate table because they need to store multiple values.
→ R 2 also have separate table by considering Primary keys M and N as foreign keys.
→ R 1 is converted to many side table i.e., N as Primary key and M as Foreign key.
So, totally we need 3 tables to store the value.
R 1 is one to many.
R 2 is many to many.
→ M and N have separate table because they need to store multiple values.
→ R 2 also have separate table by considering Primary keys M and N as foreign keys.
→ R 1 is converted to many side table i.e., N as Primary key and M as Foreign key.
So, totally we need 3 tables to store the value.
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