rollback

问题 How can I undo the most recently executed mysql query? 回答1: If you define table type as InnoDB, you can use transactions. You will need set AUTOCOMMIT=0 , and after you can issue COMMIT or ROLLBACK at the end of query or session to submit or cancel a transaction. ROLLBACK -- will undo the changes that you have made 回答2: You can only do so during a transaction. BEGIN; INSERT INTO xxx ...; DELETE FROM ...; Then you can either: COMMIT; -- will confirm your changes Or ROLLBACK -- will undo your

问题 I am wondering, if there is a possibility to apply conditional transaction rollback based on state of particular batch. For example, I have a following code: BEGIN TRAN --EXEC No 1 EXEC [dbo].[MyProc] 1; GO --EXEC No 2 EXEC [dbo].[MyProc] 22; GO --EXEC No 3 EXEC [dbo].[MyProc] 333; GO --EXEC No 4 EXEC [dbo].[MyProc] 5; GO COMMIT And I want to rollback entire transaction if the EXEC No 3 fails. If any other execution fails I want SQL Server to continue executing my query. Is it possible? 回答1:

问题 I need to use a Transaction Scope with Entity Framework 4 and a Firebird database. I am using the FireBird Entity Framework provider. My problem is that once SaveChanges has been called on an object, the data is persisted to the database, instead of when transactionScope.Complete() is called. This results in data never rolling back, even if an exception occurs inside the using (TransactionScope ...) block. This seems to be a problem with the FireBird DB, I have tested the exact same code with

问题 In my rails app, I have a transaction block in a controller's create action in which I attempt to create two records. def create ActiveRecord::Base.transaction do @foo = Foo.new(params[:foo].except(:bar)) raise ActiveRecord::Rollback unless @foo.save @bar = Bar.new(params[:foo][:bar]) raise ActiveRecord::Rollback unless @bar.save end end I'd like to be able to rescue from the Rollback so I can return an error indicating which save failed. rescue ActiveRecord::Rollback => e @foo.errors = e if

问题 I have some code that uses an Informix 11.5 database that I want to run some tests against. If the tests fail they will often leave the database in an inconsistent state that needs to be manually resolved before the tests can be run again. I would like to automate this so that the tests do not require manual intervention before running the tests again. My current solution is to write some code that does the cleanup, but this means the code must be maintained whenever potential new

问题 I connected the database using Entity Framework . I Implemented a Contact Repository to Save the Contact Information (Sample Repository). In the Said Class file, I declared a static property for handling DBEntities (i.e., BLabsEntities ) namely " Context " and also declared a static property for DbContextTransaction . In the following code I added a try catch block to handle Exceptions of Entity Framework in the SaveContact() Repository method. I Initiated a transaction before starting the

问题 Let's assume we have a bunch of LINQ2SQL InsertOnSubmit statements against a given DataContext . If the SubmitChanges call is successful, is there any way to automatically generate a list of SQL commands (or even LINQ2SQL statements) that could undo everything that was submitted at a later time? It's like executing a rollback even though everything worked as expected. Note: The destination database will either be Oracle or SQL Server, so if there is specific functionality for both databases

问题 In transact-sql, what is the purpose of enclosing different actions between "begin transaction" and "commit transaction" I noticed that when an exception is thrown in the middle of the function It Does not roll back the transaction. if an error occurs, How to roll back the transaction? 回答1: Best way to have proper error handling using try and catch. Then do actions in catch clause based on the error like roll back tran or etc. However, if you do not want to change the code at all.Specify

问题 In transact-sql, what is the purpose of enclosing different actions between "begin transaction" and "commit transaction" I noticed that when an exception is thrown in the middle of the function It Does not roll back the transaction. if an error occurs, How to roll back the transaction? 回答1: Best way to have proper error handling using try and catch. Then do actions in catch clause based on the error like roll back tran or etc. However, if you do not want to change the code at all.Specify

问题 Is there a way in SQLite to essentially undo the latest transaction after it has been committed? I'd like to revert the database to the state before a transaction or savepoint. I've looked at the rollback command, but it looks like it is limited to rolling back a pending transaction. Edit Could I create a savepoint named "Undo" and wait to release it before starting the next action, or rollback if I need to undo it? 回答1: I am not sure if you are using JDBC 3.0. If you are then it supports