rollback

问题 I'd like to know what the best way of exception handling in data access objects is, I'm interested in production quality code. As an example public UserDaoImpl implements UserDao{ @PersistenceContext private EntityManager em; void save(User user){ em.persist(user); } User getById(long id){ return em.find(User.class,id); } } Let's say that for example I have a RegisterService somewhere where at some point I'd like to save the user to the database. And that each User needs to have a unique

问题 I'm using GreenDao to store a lot of data, coming from a REST service . A lot of my entities are connected with relations. Everything works great, but tomorrow I have to implement a rocksolid workflow. When I load my data I have to check if an error occurs . If so, I have to make sure nothing is stored in the SQLite DB. Normally I would work with transactions and rollback in case of an exception, otherwise commit to the db. For now I just use insertordelete to save an entity, everytime I

问题 How can I make Oracle 11g rollback the whole transaction on any error in included SQL file? The file contents are: set autocommit off whenever SQLERROR EXIT ROLLBACK insert into a values (1); insert into a values (2); drop index PK_NOT_EXIST; commit; And the file is included into sqlplus session using "@": @error.sql As expected, the sqlplus session terminates and the output is SQL> @error.sql 1 row created. 1 row created. drop index PK_NOT_EXIST * ERROR at line 1: ORA-01418: specified index

问题 I have a custom action <CustomAction Id="myActionId" BinaryKey="myAction" DllEntry="MySimpleAction" Execute="immediate" Return="check" /> <InstallExecuteSequence> <Custom Action="myActionId" After="InstallInitialize">CHECKBOXCOPYPROP=1</Custom> </InstallExecuteSequence> My custom action does backup and resolved database. I need to do rollback (drop database) when is canceled installation. I did: <CustomAction Id="myActionId" BinaryKey="myAction" DllEntry="MySimpleAction" Execute="immediate"

问题 I need to update a specific column of a table ( bigtable ) containing ids of another table (FK constraint to oldsmalltable ) to point to ids on another table (FK constraint to newsmalltable ). Basically this is what I am doing: DELIMITER // CREATE PROCEDURE updatebigtable () BEGIN DECLARE EXIT HANDLER FOR SQLEXCEPTION, SQLWARNING ROLLBACK; START TRANSACTION; ALTER TABLE bigtable DROP FOREIGN KEY bigtable_ibfk_1, MODIFY smalltable_id SMALLINT ; UPDATE bigtable SET smalltable_id=CASE smalltable

问题 I'm using Spring + Hibernate + H2. I do database operations in my integration tests (by calling a service class). I want Spring to rollback the changes after each test method, but I can't get it to work. At first I used MySQL (with MyISAM, which doesn't support transaction), but after changing to H2 the problem remains. I tried several DataSource-definitions (after reading that it must be XA-aware), but nothing seems to help. I use http://code.google.com/p/generic-dao/ for my DAO-classes and

问题 Normally when I do $ rake db:rollback it rolls back one migration. But now, repeatedly times, it has rollbacked 3 steps. How come this behaviour? I'm on Rails 3.2.13. 回答1: You can specify the number of steps like this: rake db:rollback STEP=3 The STEP parameter is actually an environment variable here. If, in your terminal, you run the command echo $STEP , does it return 3? If it does, you can execute export STEP=1 to get back to expected behaviour. If it happens again, try to find out where

问题 While editing some records in my PostgreSQL database using sql in the terminal (in ubuntu lucid), I made a wrong update. Instead of - update mytable set start_time='13:06:00' where id=123; I typed - update mytable set start_time='13:06:00'; So, all records are now having the same start_time value. Is there a way to undo this change? There are some 500+ records in the table, and I do not know what the start_time value for each record was Is it lost forever? 回答1: I'm assuming it was a

问题 I am learning Spring and I have some troubles with transaction in Spring. Here is my code @Transactional(rollbackFor = Exception.class) public void createGroupStudent(Student A,Student B,String nameGroup){ try{ //create Group createGroup(nameGroup); //createMember createMember(A,B); }catch(Exception e){ logger.error(e.getMessage()); } } @Transactional(rollbackFor = Exception.class) public void createGroup(String nameGroup){ try{ repoGroup.save(nameGroup); }catch(Exception e){ logger.error(e

问题 In the document Oracle Database PL/SQL Language Reference 11g Release 2 (11.2), the "Implicit Rollbacks" section begins with this text: "Before running an INSERT, UPDATE, DELETE, or MERGE statement, the database marks an implicit savepoint (unavailable to you). If the statement fails, the database rolls back to the savepoint . Usually, just the failed SQL statement is rolled back, not the whole transaction." So if I run a SQL sentence into an PL/SQL program, and the sentence fails, then the