Does an Interrupted UPDATE still manipulate data?

Question

i have fired an 'update' query by mistake. But while processing i canceled the transaction. I want to know during that time of execution and cancellation has any data got manipulated.

Answer 1

What sort of query?

If it was a plain SELECT, then no damage will have been done.

If it was in a transaction, then the transaction should have been rolled back - and any damage should have been undone.

If the operation was not running in a transaction, the behaviour will be DBMS-specific. Most will treat statements as atomic - either it completes or it is as if the statement was never executed. Not all do things that way, though.

It would help if you specified which DBMS you are using - there can be differences in the answer depending on the nuances of the DBMS in question.

Answer 2

But while processing i cancelled the transaction.

WP - Basically, if it was a transaction, and you canceled it before it finished, then whatever had started would have been undone. What your database looks like now should be the same as it looked before the UPDATE.