# Questions 1. Joe Bloggs is helping us build Scaler. He is trying to delete some batches but the database throws an error that the batch is used by a tuple in another table. Which type of integrity constraint is being enforced here? >A. User-defined integrity \ B. Domain integrity \ C. Entity integrity \ D. Referential integrity --- 2. Which of the following is not an example of domain integrity constraints? >A. Validating that input is correct data type \ B. Ensuring value is not null if a non-nullable column \ C. Making sure each row is unique \ D. Checking if the value exceeds maximum length --- 3. Joe Bloggs is taking some time off to build his house. A house can have many rooms. What is the cardinality of house to room? >A. One to Many (1:m) \ B. One to One (1:1) \ C. Many to Many (m:n) --- 4. Let us say a house has a house_id and a room has room_id. Given the cardinality of house to room, which is the ideal place to store their relationship i.e. reference? >A. room_id in house \ B. Separate table for room_id and house_id \ C. Array of room_ids in house \ D. house_id in room --- # Answers 1. D. `Referential integrity` 2. C `Making sure each row is unique` 3. A `One to Many (1:m)` 4. D `house_id in room`