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;

Which SQL keyword undoes all changes made during the transaction?

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;

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

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;

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

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

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;

What does this command do? ROLLBACK TO SAVEPOINT sp1;

Which of the following options shows a correct transaction that ensures both statements execute or none?

Which isolation level prevents dirty reads?

What will happen if COMMIT is not issued after a transaction? BEGIN TRANSACTION; UPDATE employees SET salary = salary + 1000 WHERE id = 10;

What is the result of executing the following? BEGIN; UPDATE customer SET points = points + 10 WHERE id = 1; ROLLBACK;

What is true about COMMIT?

What is the default behavior of most DBMS when executing SQL statements outside a transaction block?

Which of these statements is true about a transaction?

Which of the following represents a consistent transaction?

What will this do? BEGIN; UPDATE items SET quantity = quantity - 5 WHERE id = 10; SAVEPOINT before_discount; UPDATE items SET price = price * 0.9 WHERE id = 10; ROLLBACK TO before_discount; COMMIT;

Which command releases a savepoint?

What does the following trigger do? CREATE TRIGGER trg_before_insert BEFORE INSERT ON employees FOR EACH ROW SET NEW.hire_date = NOW();

Which event is used in this trigger? CREATE TRIGGER trg_after_delete AFTER DELETE ON orders FOR EACH ROW BEGIN INSERT INTO audit_log(action) VALUES ('Order deleted'); END;

What will be the effect of this trigger? CREATE TRIGGER trg_prevent_salary_update BEFORE UPDATE ON employees FOR EACH ROW BEGIN IF OLD.salary <> NEW.salary THEN SIGNAL SQLSTATE '45000' SET MESSAGE_TEXT = 'Salary update not allowed'; END IF; END;

What type of trigger is this? CREATE TRIGGER trg_update_timestamp BEFORE UPDATE ON products FOR EACH ROW SET NEW.updated_at = NOW();

Which keyword ensures the trigger is run for each affected row?

Which table does the trigger below affect? CREATE TRIGGER trg_check_quantity BEFORE INSERT ON order_items FOR EACH ROW BEGIN IF NEW.quantity > 100 THEN SET NEW.quantity = 100; END IF; END;

Identify the error in this trigger. CREATE TRIGGER trg_error_example AFTER INSERT ON users BEGIN UPDATE stats SET count = count + 1; END;

Which of the following can a trigger NOT do?

What does OLD refer to? IF OLD.status = 'active' THEN -- some logic END IF;

What happens if a trigger has a syntax error?

Which clause defines the timing of this trigger? CREATE TRIGGER log_change AFTER UPDATE ON logs

What is the purpose of NEW in this trigger? CREATE TRIGGER trg_before_insert_customer BEFORE INSERT ON customers FOR EACH ROW SET NEW.created_at = NOW();

What happens if you try to insert NULL for NOT NULL field but use trigger to set value? CREATE TRIGGER set_default BEFORE INSERT ON test FOR EACH ROW SET NEW.name = 'Default';

Which part specifies the trigger name? CREATE TRIGGER trg_update_log AFTER UPDATE ON table_name ...

What will this trigger do? CREATE TRIGGER prevent_delete BEFORE DELETE ON employees FOR EACH ROW BEGIN SIGNAL SQLSTATE '45000' SET MESSAGE_TEXT = 'Cannot delete employee'; END;

What is the trigger scope here? FOR EACH ROW

Which trigger runs only once per operation, not per row?

Which of these is a valid trigger event?

Which command deletes a trigger?

What does this trigger do? CREATE TRIGGER trg_bonus AFTER INSERT ON sales FOR EACH ROW BEGIN UPDATE employees SET bonus = bonus + 100 WHERE id = NEW.emp_id; END;