What is the use of Referential Integrity in MS Access?

Solution (By Examveda Team)

In Microsoft Access, Referential Integrity is a database property that enforces the relationship between tables in a relational database. It ensures that the relationships between records in different tables are maintained accurately. The options presented describe the effects of enabling referential integrity between tables:

Option A: This option is incorrect. Referential integrity does not allow entering a value in the foreign key field of a child table unless that value exists in the primary key of the parent table. In other words, it enforces the rule that the foreign key value must have a corresponding value in the primary key of the related table.
Option B: The correct option. Referential integrity does not allow entering a value in the foreign key field of a child table if that value exists in the primary key of the parent table. This ensures that relationships are maintained accurately and prevents the creation of orphaned records in the child table that do not have a corresponding parent record.
Option C: This option is incorrect. The description provided is not accurate. Referential integrity primarily concerns the relationship between a foreign key in a child table and the primary key in a parent table, not the other way around.
Option D: None of the provided options accurately represent the effects of referential integrity.

Therefore, the correct option is Option B: It does not allow to enter a value in the foreign key field of a child table if that value exists in the primary key of the parent table. This ensures that data integrity is maintained by preventing inconsistent relationships between tables.