Question

Please help me answer these:

In the relational database model, an entity consists of one and only one entity instance (or record).

A. True B. False

2. In the relational database model, the foreign key name does NOT have to be the same as the primary key name.

A. True B. False

3. Logical relationships between tables (or entities) in the relational database model are created with primary and candidate keys.

A. True B. False

4. In the relational database model, each primary key value should be unique and should NOT be Null.

A. True B. False

5. In the design step of SDLC, the system is created and developed (i.e., written in code).

A. True B. False

Answer 1

Here, correct answer is False

Explanation:

In the Relational database model, an entity can contain one or more than one entity instance, here, number of entity instances allotted to the entity in relationship, hence, statement is not correct.

Here, correct answer is False

Explanation:

As, in the relational database model, Foreign key could be chosen as same name as the primary key name of the another table, hence, statement is False

Here, correct answer is True,

Explanation:

As Logical relationship between the tables or entities in the relational database model that can include primary and candidate keys, hence, statement is correct.

Here, correct answer is True,

Explanation:

In the relational database model, each primary key has to be unique one and It can’t be null, hence, statement is correct.

Here, correct answer is False,

Explanation:

As, in the design stage of SDLC, It describe about the system in more details, however, system is Not created, developed and delivered, hence, statement is wrong or false.