? ROLLBACK in SQL

The ROLLBACK statement is used to undo changes made in a transaction before they are committed. It helps maintain data integrity by reverting data to its previous state.

? Syntax:

ROLLBACK;

? When to Use:

• If an error occurs during a transaction

• If you want to cancel pending changes

• To test data manipulation safely

? Example with Transaction:

BEGIN;UPDATE accounts SET balance = balance - 500 WHERE account_id = 1;UPDATE accounts SET balance = balance + 500 WHERE account_id = 2;-- Something goes wrongROLLBACK;  -- This undoes both updates

? Example in MySQL:

START TRANSACTION;DELETE FROM employees WHERE emp_id = 101;-- Oops! Wrong IDROLLBACK;

? Example in SQL Server:

BEGIN TRANSACTION;UPDATE orders SET status = 'Canceled' WHERE order_id = 5;-- Undo itROLLBACK TRANSACTION;

? Notes:

• Works only if autocommit is off (or inside explicit transaction).

• Must be issued before COMMIT; otherwise, changes are saved and cannot be rolled back.

? Related Commands:

Need a full transaction flow with error handling?