Databases

Question 1

List

Types of Database Integrity

Answer 1

• Domain
• Relational
• Entity

(DRE)

Question 2

Define

Domain Integrity

Answer 2

Values in a column must be valid and match type & format

e.g. text must go in a TEXT column

Question 3

Define

Referential Integrity

Answer 3

Foreign keys must point to a valid primary key.

Question 4

Define

Entity Integrity

Answer 4

Every row has a primary key that is unique

(Unique entity)

Question 5

List

Types of Data Anomalies

Answer 5

• Update
• Insert
• Delete

(UID)

Question 6

Define

Update Anomaly

Answer 6

Updating data stored in multiple locations that aren’t linked together

Question 7

Insert Anomaly

Answer 7

When new data can’t be added due to its relationship with other data

(e.g. a db with a student id and course id, a new student id can’t be added without having a null course id)

Question 8

Delete Anomaly

Answer 8

When deleting one piece of data leads to the deletion of another piece of data

(e.g. car rego database, where a person is deleted and their only car is deleted as a result)