Question

Q 22 Identify the correct statement about Foreign Key.
3
Ops: A
B.
O A data element/attribute within a data field of a data record that is not unique,
and cannot be used to distinguish one data record in a database from another data record within a database table.
O A data element/attribute within a data field of a data record within a database table that is a secondary key in another database table.
O A data element/attribute within a data field of a data record within a database table that is a primary key in another database table.
O A data element/attribute within a data field of a data record that enables a database to uniquely distinguish one data record in a database from
another data record within a database table.
C.
D.​

Answer 1

Explanation:

didn't understand the question!!

Answer 2

Answer:

The correct choice is (C) A data element/attribute within a data field of a data record within a database table that is a primary key in another database table

Explanation:

The best  can explain:

• A FOREIGN KEY constraint can reference columns in tables in the same database or within the same table.
• These are called self-referencing tables.
• For example, consider an employee table that contains three columns: employee_number, employee_name, and manager_employee_number.
• Because the manager is also an employee, there is a foreign key relationship from the manager_employee_number column to the employee_number column.