Question

How can I test an UPDATE statement for example to see if it would work, for example if it would actually update rows etc?

Is there a way to simulate it easily?

Answer 1

Use a transaction to wrap your update statement and a select query (to test the update) and then always roll it back.

Example:

BEGIN;

UPDATE accounts SET balance = balance - 100.00
    WHERE name = 'Alice';

SELECT balance FROM accounts WHERE name = 'Alice';

ROLLBACK; -- << Important! Un-does your UPDATE statement above!

A transaction typically ends with a commit but since you’re just testing and do not want the changes to be permanent you will just roll back.