SQL Transaction and Trigger Quiz

Which SQL command is used to start a transaction?

• START TRANSACTION

• BEGIN

• BEGIN TRANSACTION

• INITIATE

What does the following SQL snippet do? BEGIN TRANSACTION; UPDATE accounts SET balance = balance - 500 WHERE id = 101; UPDATE accounts SET balance = balance + 500 WHERE id = 102; COMMIT;

• Performs a rollback

• Transfers money from one account to another

• Locks the entire table

• Fails due to syntax error

Which SQL keyword undoes all changes made during the transaction?

• ROLLBACK

• COMMIT

• UNDO

• CANCEL

Consider this code: What happens if the second update fails? BEGIN TRANSACTION; UPDATE inventory SET stock = stock - 10 WHERE item_id = 5; UPDATE sales SET quantity = quantity + 10 WHERE item_id = 5; COMMIT;

• The first update is committed

• Both updates are rolled back

• Both updates are committed

• Error is ignored

What does this code ensure? BEGIN; UPDATE table1 SET col = 'value'; COMMIT;

• Durability only

• Isolation only

• Atomicity

• None of the above

What is missing to make this transaction atomic? UPDATE orders SET status = 'shipped' WHERE id = 123; UPDATE inventory SET stock = stock - 1 WHERE product_id = 456;

• ROLLBACK

• BEGIN and COMMIT

• SAVEPOINT

• LOCK TABLE

Which of the following is used to define a point to which you can rollback later?

• CHECKPOINT

• SAVEPOINT

• MARKPOINT

• PAUSEPOINT

What will be the result of this code? BEGIN; SAVEPOINT sp1; UPDATE users SET balance = balance - 200 WHERE id = 1; ROLLBACK TO sp1; COMMIT;

• Balance will decrease by 200

• Balance will remain the same

• Transaction will be canceled

• Syntax error

Which property of transaction does this SQL snippet violate if not executed in a transaction block? UPDATE bank SET balance = balance - 100 WHERE id = 1; UPDATE bank SET balance = balance + 100 WHERE id = 2;

• Consistency

• Atomicity

• Durability

• Isolation

What does this command do? ROLLBACK TO SAVEPOINT sp1;

• Rolls back to the beginning

• Rolls back to the last COMMIT

• Rolls back to the savepoint named sp1

• Commits the savepoint