SQL Server : Rollback without BEGIN TRANSACTION

问题:

Is there a way we can rollback to previous state of the transaction using ROLLBACK without BEGIN TRANSACTION?

delete from table1;
ROLLBACK

Message:

The ROLLBACK TRANSACTION request has no corresponding BEGIN TRANSACTION.

Any input would be of great help.

Thanks !!!

回答1:

To expand on gerrytans answer when you explicitly set IMPLICIT_TRANSACTIONS ON, you can use a ROLLBACK. See the MSDN doco related to this. Note that this isn't the default autocommit transaction mode.

This allows me to run a statement like;

SET IMPLICIT_TRANSACTIONS ON

INSERT INTO my_table (item_type, start_date_time)
VALUES ('TEST', CURRENT_TIMESTAMP)

ROLLBACK

-- Shouldn't return the 'TEST' value inserted above.
SELECT * FROM my_table ORDER BY start_date_time DESC 

回答2:

As SQL server error tells you -- no you can't. And many people would be curious why would you want that in the first place.

Keep in mind SQL server has an implicit transaction -- that is for DML you issue without explicit BEGIN TRAN, SQL server will start and finish a transaction for you behind the screen.

A common usage of ROLLBACK is for error handling. If somewhere in the middle of the transaction you realize you cannot proceed further due to bad user input or other reason -- then a reasonable action is to ROLLBACK to return to the starting point

The worst thing that can happen is leave your data state 'somewhere in the middle'.

回答3:

You must have a BEGIN TRANSACTION before you can use the ROLLBACK command. You can't go back to the previous state.