There is no rollback option (rollback has a different meaning in a MongoDB context), and strictly speaking there is no supported way to get these documents back – the precautions you can/should take are covered in the comments. With that said however, if you are running a replica set, even a single node replica set, … Read more
using (var Conn = new SqlConnection(_ConnectionString)) { SqlTransaction trans = null; try { Conn.Open(); trans = Conn.BeginTransaction(); using (SqlCommand Com = new SqlCommand(ComText, Conn, trans)) { /* DB work */ } trans.Commit(); } catch (Exception Ex) { if (trans != null) trans.Rollback(); return -1; } } or you could go even cleaner and easier and … Read more
First of all, there is no rollback of an exception, it’s a rollback of a transaction. If you throw your exception with @ApplicationException(rollback=true), you don’t have to rollback the transaction manually. Context.setRollbackOnly() forces the container to rollback the transaction, also if there is no exception. A checked exception itself doesn’t rollback a transaction. It needs … Read more
rake db:rollback STEP=1 Is a way to do this, if the migration you want to rollback is the last one applied. You can substitute 1 for however many migrations you want to go back. For example: rake db:rollback STEP=5 Will also rollback all the migration that happened later (4, 3, 2 and also 1). To … Read more
If you are dealing with production-grade systems then yes, it is very bad. If it is your own pet project, then anything is allowed (if nothing else, it will be a learning experience 🙂 though chances are that sooner rather than later, even in a pet project, you will find yourself having put a cross … Read more
Suppose you have a single file in your repo, and you have the following commits: commit 1 : the file contains A commit 2 : the file contains B commit 3 : the file contains C If you execute revert on commit 3, you’ll have this in the repo: commit 1 : the file contains … Read more
It would not be a good idea to rollback sequences. Imagine two transactions happening at the same time, each of which uses the sequence for a unique id. If the second transaction commits and the first transaction rolls back, then the second inserted a row with “2” while the first rolls the sequence back to … Read more
Yes, everything that you do between the Begin Transaction and Commit (or Rollback) is part of the transaction.
You can use 13.6.7.2. DECLARE … HANDLER Syntax in the following way: DELIMITER $$ CREATE PROCEDURE `sp_fail`() BEGIN DECLARE `_rollback` BOOL DEFAULT 0; DECLARE CONTINUE HANDLER FOR SQLEXCEPTION SET `_rollback` = 1; START TRANSACTION; INSERT INTO `tablea` (`date`) VALUES (NOW()); INSERT INTO `tableb` (`date`) VALUES (NOW()); INSERT INTO `tablec` (`date`) VALUES (NOW()); — FAIL IF … Read more
These commands all come from Mercurial itself, and there are plenty of good compare/contrast posts for them. However, here they are in brief: rollback: one-level undo. Will undo the last pull or commit (can be dangerous) backout: create a new commit that is the inverse of a given commit. Net effect is an undo, but … Read more