Question

Suppose TeacherID is the primary key of one table (e.g., the Teachers table) and the foreign key of another table (e.g., the TopPayingJobs table). If you can’t enforce the referential integrity relationship between these two tables, what might be the cause?

a. The values of the primary key column are referenced by the values of the foreign key column.

b. The foreign key contains duplicate data.

c. The foreign key column contains values that do not exist in the primary key column.

d. None of the above.

Answer 1

If you can’t enforce the referential integrity relationship between these two tables then The foreign key column contains values that do not exist in the primary key column.

Referential integrity gives the following properties of the data

• Accuracy of the data and
• Consistency of the data

If there is no referential integrity, it indicates that there is a record in foreign key which is not exist in the primary key.

No referential integrity found when delete a record in the primary key table which is referred by the foreign key table.

Option C