In many-to-many relationships in a relational database design,________.
A) the key of the child is placed as a foreign key into the parent
B) the key of the parent is placed as a foreign key into the child
C) the keys of both tables are placed in a third table
D) the keys of both tables are joined into a composite key
E) Both C and D

Question

Quizplus · Accepted Answer

In many-to-many relationships, it is not possible to place the key of one table directly into the other table as a foreign key. Therefore, the keys of both tables are placed in a third table (option C) which is called a junction or linking table. The junction table contains the foreign keys referencing the primary keys of both tables. To enforce referential integrity, a composite key is created by joining the foreign keys of both tables in the junction table (option D). Therefore, the best choice is E, which includes both C and D as correct options.

In Many-To-Many Relationships in a Relational Database Design,________