Question 1

To represent a M:N relationship in the relational model,an intersection table is created to represent the relationship itself.

Accepted Answer

An intersection table is indeed created in the relational model to represent a M:N relationship. It contains foreign keys from the two related entities and can store additional attributes related to the relationship itself.

Question 2

The technique for representing E-R relationships in the relational model is dependent on the minimum cardinality.

Accepted Answer

This statement is false. The technique for representing E-R relationships in the relational model is not dependent on the minimum cardinality. In fact, the technique is based on the maximum cardinality, which determines the type of relationship (one-to-one, one-to-many, many-to-many) and how it should be represented in the relational model.

Question 3

In the relational model,many-to-many relationships cannot be directly represented by relations the way 1:1 and 1:N relationships can.

Accepted Answer

Many-to-many relationships require the use of an intermediary or junction table to bridge the two related tables, which cannot be directly represented as relations in the relational model.

Question 4

Which of the following is true when representing a 1:1 binary relationship using the relational model?

Accepted Answer

In a 1:1 binary relationship, each instance of one entity is associated with one and only one instance of the other entity, and vice versa. Therefore, the key of either entity can be placed in the other entity as a foreign key to establish the relationship. This choice allows for flexibility in the design and does not favor one entity over the other.

Question 5

Which of the following is the correct technique for representing a 1:N relationship in the relational model?

Accepted Answer

The correct technique for representing a 1:N relationship in the relational model is to place the primary key of the entity on the one side (the parent) into the relation for the entity on the many side (the child). This establishes a foreign key relationship, allowing multiple child entities to be associated with a single parent entity.

Question 6

For a 1:1 relationship,the key of each table should be placed in the other table as the foreign key.

Accepted Answer

In a 1:1 relationship, each instance in one table is associated with exactly one instance in the other table. Therefore, the key of each table should be placed in the other table as the foreign key to establish the relationship between the two tables. This ensures that each instance in one table is linked to exactly one instance in the other table.

Question 7

Microsoft Access uses the same pure N:M relationships that occur in data modeling.

Accepted Answer

Microsoft Access uses a combination of one-to-many and many-to-many relationships, but does not support pure N:M relationships.

Question 8

When applied to 1:N relationships,the term "parent" refers to the many side of the relationship since a child may have many parents.

Accepted Answer

When applied to 1:N relationships, the term "parent" refers to the one (or "master") side of the relationship since a parent can have many children but a child can only have one parent.

Question 9

By default,Microsoft Access creates 1:1 relationships between tables.

Accepted Answer

By default, Microsoft Access creates 1:N (one-to-many) relationships between tables. A 1:1 (one-to-one) relationship can be manually created if necessary.

Question 10

Relationships that are 1:1 do not require referential integrity constraints.

Accepted Answer

Referential integrity constraints are used to ensure consistency between related tables in a database, regardless of whether the relationship is 1:1, 1:N, or N:M. In a 1:1 relationship, referential integrity ensures that each row in one table corresponds to one and only one row in the related table, and vice versa, maintaining data accuracy and consistency.

Question 11

Which of the following is the correct technique for representing a M:N relationship using the relational model?

Accepted Answer

The correct technique for representing a M:N relationship using the relational model is to create an intersection relation, and the keys of both parent entities are placed as a composite key in the intersection relation. This ensures that each possible combination of the two parent entities is unique and can be properly related to each other. Choices A, B, and D do not fully capture the complexities of a M:N relationship and may result in data integrity issues.

Question 12

To represent a 1:N relationship in the relational model,the key of either entity may be placed as a foreign key in the other entity.

Accepted Answer

In a 1:N relationship, the primary key of the entity on the "1" side is placed as a foreign key in the entity on the "N" side to establish the relationship.

Question 13

As far as Microsoft Access is concerned,there are no N:M relationships.

Accepted Answer

Microsoft Access does not support N:M relationships directly. Instead, it uses a junction table to create a many-to-many relationship between two tables.

Question 14

To represent a 1:N relationship in the relational model,the key of the entity on the one side of the relationship is placed as a foreign key in the entity on the many side of the relationship.

Accepted Answer

This statement accurately describes how a 1:N relationship is represented in the relational model. The foreign key in the entity on the many side references the primary key of the entity on the one side, allowing the relationship between the two entities to be established.

Question 15

To create a 1:1 relationship in Microsoft Access,the Indexed property of the foreign key column must be set to Yes (No Duplicates).

Accepted Answer

A 1:1 relationship in Microsoft Access requires a unique foreign key value for each record in the related table. This is achieved by setting the Indexed property of the foreign key column to Yes (No Duplicates).

Question 16

Given the tables TABLE_A (Attribute1,Attribute2,Attribute3) TABLE_B (Attribute4,Attribute5,Attribute6) As shown in the figure below,which of the following would display the correct placement of foreign keys in the relational model?

Accepted Answer

The answer of Given the tables TABLE_A (Attribute1,Attribute2,Attribute3) TABLE_B (Attribute4,Attribute5,Attribute6) As shown in...

Question 17

As far as Microsoft Access is concerned,there are no 1:N relationships.

Accepted Answer

Microsoft Access does support 1:N relationships between tables.

Question 18

Given the tables PRODUCT (ProductID,Description,Cost) SUPPLIER (SupplierID,ContactName,PhoneNumber) As shown in the figure below,which of the following would represent the correct placement of foreign keys?

Accepted Answer

The foreign key should be placed in the table where the relationship is one-to-many. In this case, each product can only come from one supplier (one-to-one relationship), but each supplier can supply multiple products (one-to-many relationship). Therefore, the SupplierID column should be added to the PRODUCT table as a foreign key referencing the SupplierID primary key column in the SUPPLIER table. Option E correctly places the foreign key in the PRODUCT table with the appropriate column name.

Question 19

The key for an intersection table is always the combination of the keys of the parent entities.

Accepted Answer

An intersection table's primary key is made up of the combination of the primary keys of the two parent entities it connects. This is because the purpose of an intersection table is to represent the many-to-many relationship between the two parent entities, and the combination of their primary keys is the unique identifier for each relationship instance in the intersection table.

Question 20

In certain circumstances,there may be a preference as to which table in a 1:1 relationship contains the foreign key.

Accepted Answer

In a 1:1 relationship, it is not always necessary to have a foreign key in both tables. In some cases, it may be more logical or practical to have the foreign key in one table rather than the other, depending on the specific needs and requirements of the system. For example, if one table contains more data or is accessed more frequently, it may make more sense to have the foreign key in that table. Ultimately, the choice of which table contains the foreign key should be based on the overall design and functionality of the system.

Quiz 5: Database Design