DBMS Lab Quiz 2 B3

A database application is designed to handle concurrent transactions. A user initiates a transaction to read a set of records without being affected by changes made by other transactions. Which isolation level should be set for this transaction?

• READ UNCOMMITTED

• READ COMMITTED

• REPEATABLE READ

• SERIALIZABLE

A database contains a table named students with columns student_id, student_name, and enrollment_date. A user initiates a transaction to retrieve the count of students enrolled after a specific date. Which SQL statement should be used to perform this retrieval within the transaction?

• SELECT COUNT(student_id) FROM students WHERE enrollment_date > '2023-01-01';

• COUNT students WHERE enrollment_date > '2023-01-01';

• GET COUNT(student_id) FROM students WHERE enrollment_date > '2023-01-01';

• RETRIEVE COUNT(student_id) FROM students WHERE enrollment_date > '2023-01-01';

A user initiates a transaction to retrieve the highest salary from a table named employees. Which SQL statement should be used to perform this retrieval within the transaction?

• GET MAX(salary) FROM employees;

• SELECT MAX(salary) FROM employees;

• FIND MAX(salary) IN employees;

• SEARCH MAX(salary) WITHIN employees;

A database contains a table named products with columns product_id, product_name, and quantity_in_stock. A user initiates a transaction to update the quantity in stock for a specific product with product_id = 201 to 50. Which SQL statement should be used to perform this update within the transaction?

• CHANGE products SET quantity_in_stock = 50 WHERE product_id = 201;

• UPDATE products SET quantity_in_stock = 50 WHERE product_id = 201;

• MODIFY products SET quantity_in_stock = 50 WHERE product_id = 201;

• ALTER products SET quantity_in_stock = 50 WHERE product_id = 201;

A user initiates a transaction to retrieve the distinct categories of products from a table named products. Which SQL statement should be used to perform this retrieval within the transaction?

• SELECT DISTINCT category FROM products;

• GET DISTINCT category FROM products;

• SEARCH DISTINCT category IN products;

• FIND DISTINCT category IN products;

An inventory management system records the quantity of products in a table. A user initiates a transaction to update the quantity of a specific product. If any part of the transaction fails, the system should revert to the state at the beginning of the transaction. Which SQL statement is used to roll back to a savepoint ?

• ROLLBACK 

• ROLLBACK TO SAVEPOINT 

• ROLLBACK TRANSACTION 

• UNDO TO SAVEPOINT

A user initiates a transaction to update multiple records in a table, and the changes should be isolated from other transactions until the entire transaction is committed. Which isolation level should be set for this transaction?

• READ UNCOMMITTED 

• READ COMMITTED 

• REPEATABLE READ

• SERIALIZABLE

An e-commerce website processes a customer's order, which involves deducting the item quantity from the inventory. If any part of the transaction fails, the system needs to revert all changes made by the transaction. Which SQL statement is used to roll back a transaction?

• ROLLBACK 

• CANCEL 

• REVERT 

• UNDO

With SQL, how do you select all the records from a table named “Persons” where the value of the column “FirstName” ends with an “a”?

• SELECT * FROM Persons WHERE FirstName=’a’;

• SELECT * FROM Persons WHERE FirstName LIKE ‘a%’;

• SELECT * FROM Persons WHERE FirstName LIKE ‘%a’;

• SELECT * FROM Persons WHERE FirstName=’%a%’;

A user initiates a transaction to update the status of multiple orders in a table. If any part of the transaction fails, the system needs to roll back the entire transaction. Which SQL statement is used to roll back a transaction?

• ROLLBACK 

• CANCEL 

• REVERT 

• UNDO