How to work with transactions in SQL Server Management Studio (SSMS)?

When you run T-SQL scripts in SSMS, every statement executes immediately by default. If you want to group several operations and decide later whether to keep or undo them, wrap them in a transaction.

Start with BEGIN TRAN (or BEGIN TRANSACTION):

BEGIN TRAN
UPDATE Accounts SET Balance = Balance - 100 WHERE AccountID = 1;
UPDATE Accounts SET Balance = Balance + 100 WHERE AccountID = 2;

At this point, the changes are pending but not permanent. You can verify the results in another query window or use SELECT @@TRANCOUNT to see if a transaction is open.

To keep the changes:

COMMIT TRAN

To undo them:

ROLLBACK TRAN

Tip: you can enable "Implicit Transactions" mode in SSMS under Query - Options - Execution - ANSI, so that each statement starts a transaction automatically. Then commit or rollback manually when you're done.

Transactions are the safest way to test data updates. You can practice on live data without leaving permanent changes behind.