Transactions

Use the same database and complete each block within one client session. The examples begin with Alice as the employee whose identifier is 1.

Roll Back a Change

BEGIN;
UPDATE employees SET name = 'Temporary' WHERE id = 1;
ROLLBACK;

BEGIN opens an explicit transaction. The UPDATE changes the name within that transaction; ROLLBACK discards the change.

SELECT id, name FROM employees ORDER BY id;

The names remain Alice, Boris and Clara. The same result is visible after closing the client and reopening the file database.

Commit a Change

BEGIN;
UPDATE employees SET name = 'Alicia' WHERE id = 1;
COMMIT;

Run the SELECT again. Employee 1 is now Alicia; Boris and Clara are unchanged. COMMIT completes the transaction and makes its change persistent according to the configured durability mode.

Do not split BEGIN and COMMIT between separate CLI processes. Closing a client is not a substitute for an explicit commit. These examples demonstrate a single-client transaction; they do not define concurrent isolation behavior.

Finish

Enter exit after completing the transaction. You may keep the tutorial database for later exercises. To discard it, first inspect the value of tutorial_dir in the original shell and remove only the temporary directory created for this tutorial. Never run cleanup against a working database.

The next step is a server connection. The local CLI opens files directly, so a TCP client is needed for that mode. Server installation, connection parameters and security restrictions are covered by the administration and client-interface parts of the manual.