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  • Can an ActiveRecord before_save filter halt the save without halting the transaction?

    - by Michael Boutros
    Is there any way for a before_save filter to halt the entire save without halting the transaction? What I'm trying to do is have a "sample" version of my model that the user can interact with and save but the changes themselves are never actually saved. The following will halt the transaction and (naturally) return false when I call @model.update_attributes: before_filter :ignore_changes_if_sample def ignore_changes_if_sample if self.sample? return false end end Thanks!

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  • SQL SERVER – How to Roll Back SQL Server Database Changes

    - by Pinal Dave
    In a perfect scenario, no unexpected and unplanned changes occur. There are no unpleasant surprises, no inadvertent changes. However, even with all precautions and testing, there is sometimes a need to revert a structure or data change. One of the methods that can be used in this situation is to use an older database backup that has the records or database object structure you want to revert to. For this method, you have to have the adequate full database backup and a tool that will help you with comparison and synchronization is preferred. In this article, we will focus on another method: rolling back the changes. This can be done by using: An option in SQL Server Management Studio T-SQL, or ApexSQL Log The first two solutions have been described in this article The disadvantages of these methods are that you have to know when exactly the change you want to revert happened and that all transactions on the database executed in a specific time range are rolled back – the ones you want to undo and the ones you don’t. How to easily roll back SQL Server database changes using ApexSQL Log? The biggest challenge is to roll back just specific changes, not all changes that happened in a specific time range. While SQL Server Management Studio option and T-SQL read and roll forward all transactions in the transaction log files, I will show you a solution that finds and scripts only the specific changes that match your criteria. Therefore, you don’t need to worry about all other database changes that you don’t want to roll back. ApexSQL Log is a SQL Server disaster recovery tool that reads transaction logs and provides a wide range of filters that enable you to easily rollback only specific data changes. First, connect to the online database where you want to roll back the changes. Once you select the database, ApexSQL Log will show its recovery model. Note that changes can be rolled back even for a database in the Simple recovery model, when no database and transaction log backups are available. However, ApexSQL Log achieves best results when the database is in the Full recovery model and you have a chain of subsequent transaction log backups, back to the moment when the change occurred. In this example, we will use only the online transaction log. In the next step, use filters to read only the transactions that happened in a specific time range. To remove noise, it’s recommended to use as many filters as possible. Besides filtering by the time of the transaction, ApexSQL Log can filter by the operation type: Table name: As well as transaction state (committed, aborted, running, and unknown), name of the user who committed the change, specific field values, server process IDs, and transaction description. You can select only the tables affected by the changes you want to roll back. However, if you’re not certain which tables were affected, you can leave them all selected and once the results are shown in the main grid, analyze them to find the ones you to roll back. When you set the filters, you can select how to present the results. ApexSQL Log can automatically create undo or redo scripts, export the transactions into an XML, HTML, CSV, SQL, or SQL Bulk file, and create a batch file that you can use for unattended transaction log reading. In this example, I will open the results in the grid, as I want to analyze them before rolling back the transactions. The results contain information about the transaction, as well as who and when made it. For UPDATEs, ApexSQL Log shows both old and new values, so you can easily see what has happened. To create an UNDO script that rolls back the changes, select the transactions you want to roll back and click Create undo script in the menu. For the DELETE statement selected in the screenshot above, the undo script is: INSERT INTO [Sales].[PersonCreditCard] ([BusinessEntityID], [CreditCardID], [ModifiedDate]) VALUES (297, 8010, '20050901 00:00:00.000') When it comes to rolling back database changes, ApexSQL Log has a big advantage, as it rolls back only specific transactions, while leaving all other transactions that occurred at the same time range intact. That makes ApexSQL Log a good solution for rolling back inadvertent data and schema changes on your SQL Server databases. Reference: Pinal Dave (http://blog.sqlauthority.com)Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL Tagged: ApexSQL

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  • ASP.NET 2.0 app runs on Win 2003 in IIS 5 isolation mode but not in (default) IIS 6 mode

    - by Tex
    The app uses DLLImport to call a legacy unmanaged dll. Let's call this dll Unmanaged.dll for the sake of this question. Unmanaged.dll has dependencies on 5 other legacy dll's. All of the legacy dll's are placed in the WebApp/bin/ directory of my ASP.NET application. When IIS is running in 5.0 isolation mode, the app works fine - calls to the legacy dll are processed without error. When IIS is running in the default 6.0 mode, the app is able to initiate the Unmanaged.dll (InitMe()), but dies during a later call to it (ProcessString()). I'm pulling my hair out here. I've moved the unmanaged dll's to various locations, tried all kinds of security settings and searched long and hard for a solution. Help! Sample code: [DllImport("Unmanaged.dll", EntryPoint="initME", CharSet=System.Runtime.InteropServices.CharSet.Ansi, CallingConvention=CallingConvention.Cdecl)] internal static extern int InitME(); //Calls to InitMe work fine - Unmanaged.dll initiates and writes some entries in a dedicated log file [DllImport("Unmanaged.dll", EntryPoint="processString", CharSet=System.Runtime.InteropServices.CharSet.Ansi, CallingConvention=CallingConvention.Cdecl)] internal static extern int ProcessString(string inStream, int inLen, StringBuilder outStream, ref int outLen, int maxLen); //Calls to ProcessString cause the app to crash, without leaving much of a trace that I can find so far

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  • Why is TransactionScope operation is not valid?

    - by Cragly
    I have a routine which uses a recursive loop to insert items into a SQL Server 2005 database The first call which initiates the loop is enclosed within a transaction using TransactionScope. When I first call ProcessItem the myItem data gets inserted into the database as expected. However when ProcessItem is called from either ProcessItemLinks or ProcessItemComments I get the following error. “The operation is not valid for the state of the transaction” I am running this in debug with VS 2008 on Windows 7 and have the MSDTC running to enable distributed transactions. The code below isn’t my production code but is set out exactly the same. The AddItemToDatabase is a method on a class I cannot modify and uses a standard ExecuteNonQuery() which creates a connection then closes and disposes once completed. I have looked at other posting on here and the internet and still cannot resolve this issue. Any help would be much appreciated. using (TransactionScope processItem = new TransactionScope()) { foreach (Item myItem in itemsList) { ProcessItem(myItem); } processItem.Complete(); } private void ProcessItem(Item myItem) { AddItemToDatabase(myItem); ProcessItemLinks(myItem); ProcessItemComments(myItem); } private void ProcessItemLinks(Item myItem) { foreach (Item link in myItem.Links) { ProcessItem(link); } } private void ProcessItemComments(Item myItem) { foreach (Item comment in myItem.Comments) { ProcessItem(comment); } } Here is top part of the stack trace. Unfortunatly I cant show the build up to this point as its company sensative information which I can not disclose. Hope this is enough information. at System.Transactions.TransactionState.EnlistPromotableSinglePhase(InternalTransaction tx, IPromotableSinglePhaseNotification promotableSinglePhaseNotification, Transaction atomicTransaction) at System.Transactions.Transaction.EnlistPromotableSinglePhase(IPromotableSinglePhaseNotification promotableSinglePhaseNotification) at System.Data.SqlClient.SqlInternalConnection.EnlistNonNull(Transaction tx) at System.Data.SqlClient.SqlInternalConnection.Enlist(Transaction tx) at System.Data.SqlClient.SqlInternalConnectionTds.Activate(Transaction transaction) at System.Data.ProviderBase.DbConnectionInternal.ActivateConnection(Transaction transaction) at System.Data.ProviderBase.DbConnectionPool.GetConnection(DbConnection owningObject) at System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection) at System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory) at System.Data.SqlClient.SqlConnection.Open()

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  • SQL Server backup

    - by zzz777
    I have Full-Backup-A Transaction-Log-Backup-A Transaction-Log-Backup-B (*) - I have to restore this point Full-Backup-B How to do it? It seems that the only way is Full-Backup-A Transaction-Log-Backup-A Transaction-Log-Backup-B Shut-off client access Transaction-Log-C Full-Backup-B Allow client access Are there any other ways to guarantee that nothing did happen with the database between last transaction log and the next full backup. I was thinking about a. Starting transaction log backup simultaneously with full backup. b. Using differential back up while clients are connected and making full backup during maintenance window only c. Run replication and back-up the replica, stopping and restoring duplication services in points 4 and 7 and feel that it is actually hopeless.

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  • bad printer isolation on print server or better way?

    - by Joseph
    I have noticed that when a printer or driver screws up on a Windows server it usually locks up or kills the print spooler and everyone can't print until it is fixed. Usually we have to put the troublesome printer on another server so when it fails, it doesn't take the whole group with it. That is assuming we ever figure out which printer is the problem. Is there a way to have it so that one bad apple doesn't ruin the bunch? Even if it is another form of printer serving, that would work as long as it's not hard for the user to find a printer and install drivers.

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  • Creating queries using Criteria API (JPA 2.0)

    - by Pym
    Hello there ! I'm trying to create a query with the Criteria API from JPA 2.0, but I can't make it work. The problem is with the "between" conditionnal method. I read some documentation to know how I have to do it, but since I'm discovering JPA, I don't understand why it does not work. First, I can't see "creationDate" which should appear when I write "Transaction_." I thought it was maybe normal, since I read the metamodel was generated at runtime, so I tried to use 'Foo_.getDeclaredSingularAttribute("value")' instead of 'Foo_.value', but it still doesn't work at all. Here is my code : public List<Transaction> getTransactions(Date startDate, Date endDate) { EntityManager em = getEntityManager(); try { CriteriaBuilder cb = em.getCriteriaBuilder(); CriteriaQuery<Transaction> cq = cb.createQuery(Transaction.class); Metamodel m = em.getMetamodel(); EntityType<Transaction> Transaction_ = m.entity(Transaction.class); Root<Transaction> transaction = cq.from(Transaction.class); // Error here. cannot find symbol. symbol: variable creationDate cq.where(cb.between(transaction.get(Transaction_.creationDate), startDate, endDate)); // I also tried this: // cq.where(cb.between(Transaction_.getDeclaredSingularAttribute("creationDate"), startDate, endDate)); List<Transaction> result = em.createQuery(cq).getResultList(); return result; } finally { em.close(); } } Can someone help me to figure this out? Thanks.

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  • IDbTransaction Rollback Timeout

    - by Ben
    I am dealing with an interesting situation where I perform many database updates in a single transaction. If these updates fail for any reason, the transaction is rolled-back. IDbTransaction transaction try { transaction = connection.BeginTransaction(); // do lots of updates (where at least one fails) transaction.Commit(); } catch { transaction.Rollback(); // results in a timeout exception } finally { connection.Dispose(); } I believe the above code is generally considered the standard template for performing database updates within a transaction. The issue I am facing is that whilst transaction.Rollback() is being issued to SQL Server, it is also timing out on the client. Is there anyway of distinguishing between a timeout to issue the rollback command and a timeout on that command executing to completion? Thanks in advance, Ben

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  • In MS SQL Server, is there a way to "atomically" increment a column being used as a counter?

    - by Dan P
    Assuming a Read Committed Snapshot transaction isolation setting, is the following statement "atomic" in the sense that you won't ever "lose" a concurrent increment? update mytable set counter = counter + 1 I would assume that in the general case, where this update statement is part of a larger transaction, that it wouldn't be. For example, I think this scenario is possible: update the counter within transaction #1 do some other stuff in transaction #1 update the counter with transaction #2 commit transaction #2 commit transaction #1 In this situation, wouldn't the counter end up only being incremented by 1? Does it make a difference if that is the only statement in a transaction? How does a site like stackoverflow handle this for its question view counter? Or is the possibility of "losing" some increments just considered acceptable?

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  • Spring's EntityManager not persisting

    - by Fernando Camargo
    Well, my project was using EJB and JPA (with Hibernate), but I had to switch to Spring. Everything was working well before that. The EJB used to inject the EntityManager, controled the transaction, etc. Ok, when I switched to Spring, I had a lot of problems because I'm new on Spring. But after everything is running, I have the problem: the data is never saved on database. I configured my Spring to control the transactions, I have spring beans used in JSF, that has spring services that do the hard work. This services have a EntityManager injected and use @Transactional REQUIRED. This services pass the EntityManager to a DAO that call entityManager.persist(bean). The selects appears to work well, the JTA transaction appears to work well to (I saw in log), but the entity is not saved! Here is the log: INFO: [Pronatec] - 04/04/2012 11:30:20 - [DEBUG] org.springframework.orm.jpa.support.OpenEntityManagerInViewFilter: doFilterInternal() (linha 136): Opening JPA EntityManager in OpenEntityManagerInViewFilter INFO: [Pronatec] - 04/04/2012 11:30:20 - [DEBUG] org.springframework.beans.factory.support.DefaultListableBeanFactory: doGetBean() (linha 245): Returning cached instance of singleton bean 'transactionManager' INFO: [Pronatec] - 04/04/2012 11:30:20 - [DEBUG] org.springframework.orm.hibernate3.HibernateTransactionManager: getTransaction() (linha 365): Creating new transaction with name [br.org.cni.pronatec.controller.service.MontanteServiceImpl.adicionarValor]: PROPAGATION_REQUIRED,ISOLATION_DEFAULT; '' INFO: [Pronatec] - 04/04/2012 11:30:20 - [DEBUG] org.springframework.orm.hibernate3.HibernateTransactionManager: doBegin() (linha 493): Opened new Session [org.hibernate.impl.SessionImpl@2b2fe2f0] for Hibernate transaction INFO: [Pronatec] - 04/04/2012 11:30:20 - [DEBUG] org.springframework.orm.hibernate3.HibernateTransactionManager: doBegin() (linha 504): Preparing JDBC Connection of Hibernate Session [org.hibernate.impl.SessionImpl@2b2fe2f0] INFO: [Pronatec] - 04/04/2012 11:30:20 - [DEBUG] org.springframework.orm.hibernate3.HibernateTransactionManager: doBegin() (linha 569): Exposing Hibernate transaction as JDBC transaction [com.sun.gjc.spi.jdbc40.ConnectionHolder40@3bcd4840] INFO: [Pronatec] - 04/04/2012 11:30:20 - [DEBUG] org.springframework.orm.jpa.ExtendedEntityManagerCreator$ExtendedEntityManagerInvocationHandler: doJoinTransaction() (linha 383): Joined JTA transaction INFO: Hibernate: select hibernate_sequence.nextval from dual INFO: [Pronatec] - 04/04/2012 11:30:20 - [DEBUG] org.springframework.orm.hibernate3.HibernateTransactionManager: processCommit() (linha 752): Initiating transaction commit INFO: [Pronatec] - 04/04/2012 11:30:20 - [DEBUG] org.springframework.orm.hibernate3.HibernateTransactionManager: doCommit() (linha 652): Committing Hibernate transaction on Session [org.hibernate.impl.SessionImpl@2b2fe2f0] INFO: [Pronatec] - 04/04/2012 11:30:20 - [DEBUG] org.springframework.orm.hibernate3.HibernateTransactionManager: doCleanupAfterCompletion() (linha 734): Closing Hibernate Session [org.hibernate.impl.SessionImpl@2b2fe2f0] after transaction INFO: [Pronatec] - 04/04/2012 11:30:20 - [DEBUG] org.springframework.orm.hibernate3.SessionFactoryUtils: closeSession() (linha 800): Closing Hibernate Session INFO: [Pronatec] - 04/04/2012 11:30:20 - [DEBUG] org.springframework.orm.jpa.support.OpenEntityManagerInViewFilter: doFilterInternal() (linha 154): Closing JPA EntityManager in OpenEntityManagerInViewFilter INFO: [Pronatec] - 04/04/2012 11:30:20 - [DEBUG] org.springframework.orm.jpa.EntityManagerFactoryUtils: closeEntityManager() (linha 343): Closing JPA EntityManager In the log, I see it commiting the transaction, but I don't see the insert query (the Hibernate is printing any query). I also see that the Hibernate lookup to get the next value of the sequence ID. But after that, it never really inserts. Here is the spring context configuration: <bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean"> <property name="persistenceUnitName" value="PronatecPU" /> <property name="persistenceXmlLocation" value="classpath:META-INF/persistence.xml" /> <property name="loadTimeWeaver"> <bean class="org.springframework.instrument.classloading.InstrumentationLoadTimeWeaver"/> </property> <property name="jpaProperties"> <props> <prop key="hibernate.transaction.factory_class">org.hibernate.transaction.JTATransactionFactory</prop> </props> </property> </bean> <bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager" > <property name="transactionManagerName" value="java:/TransactionManager" /> <property name="userTransactionName" value="UserTransaction" /> <property name="entityManagerFactory" ref="entityManagerFactory" /> </bean> <bean class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor" /> <tx:annotation-driven transaction-manager="transactionManager" /> Here is my persistence.xml: <?xml version="1.0" encoding="UTF-8"?> <persistence version="1.0" xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd"> <persistence-unit name="PronatecPU" transaction-type="JTA"> <provider>org.hibernate.ejb.HibernatePersistence</provider> <jta-data-source>jdbc/pronatec</jta-data-source> <class>br.org.cni.pronatec.model.bean.AgendamentoBuscaSistec</class> <class>br.org.cni.pronatec.model.bean.AgendamentoExportacaoZeus</class> <class>br.org.cni.pronatec.model.bean.AgendamentoImportacaoZeus</class> <class>br.org.cni.pronatec.model.bean.Aluno</class> <class>br.org.cni.pronatec.model.bean.Curso</class> <class>br.org.cni.pronatec.model.bean.DepartamentoRegional</class> <class>br.org.cni.pronatec.model.bean.Dof</class> <class>br.org.cni.pronatec.model.bean.Escola</class> <class>br.org.cni.pronatec.model.bean.Inconsistencia</class> <class>br.org.cni.pronatec.model.bean.Matricula</class> <class>br.org.cni.pronatec.model.bean.Montante</class> <class>br.org.cni.pronatec.model.bean.ParametrosVingentes</class> <class>br.org.cni.pronatec.model.bean.TipoCurso</class> <class>br.org.cni.pronatec.model.bean.Turma</class> <class>br.org.cni.pronatec.model.bean.UnidadeFederativa</class> <class>br.org.cni.pronatec.model.bean.ValorAssistenciaEstudantil</class> <class>br.org.cni.pronatec.model.bean.ValorHora</class> <exclude-unlisted-classes>true</exclude-unlisted-classes> <properties> <property name="current_session_context_class" value="thread"/> <property name="hibernate.show_sql" value="true"/> <property name="hibernate.format_sql" value="true"/> <property name="hibernate.dialect" value="org.hibernate.dialect.OracleDialect"/> <property name="hibernate.transaction.manager_lookup_class" value="org.hibernate.transaction.SunONETransactionManagerLookup"/> <property name="hibernate.hbm2ddl.auto" value="update"/> </properties> </persistence-unit> </persistence> Here is my service that is injected in the managed bean: @Service @Scope("prototype") @Transactional(propagation= Propagation.REQUIRED) public class MontanteServiceImpl { // more code @PersistenceContext(unitName="PronatecPU", type= PersistenceContextType.EXTENDED) private EntityManager entityManager; // more code // The method that is called by another public method that do something before private void salvarMontante(Montante montante) { montante.setDataTransacao(new Date()); MontanteDao montanteDao = new MontanteDao(entityManager); montanteDao.salvar(montante); } // more code } My MontanteDao inherits from a base DAO, like this: public class MontanteDao extends BaseDao<Montante> { public MontanteDao(EntityManager entityManager) { super(entityManager); } } And the method that is called in BaseDao is this: public void salvar(T bean) { entityManager.persist(bean); } Like you can see, it just pick the injected entityManager and call the persist() method. The transaction is being controlled by the Spring, like is printed in the log, but the insert query is never printed in log and it is never saved. I'm sorry about my bad english. Thanks in advance for who helps.

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  • TransactionScope and Transactions

    - by Mike
    In my C# code I am using TransactionScope because I was told not to rely that my sql programmers will always use transactions and we are responsible and yada yada. Having said that It looks like TransactionScope object Rolls back before the SqlTransaction? Is that possible and if so what is the correct methodology for wrapping a TransactionScope in a transaction. Here is the sql test CREATE PROC ThrowError AS BEGIN TRANSACTION --SqlTransaction SELECT 1/0 IF @@ERROR<> 0 BEGIN ROLLBACK TRANSACTION --SqlTransaction RETURN -1 END ELSE BEGIN COMMIT TRANSACTION --SqlTransaction RETURN 0 END go DECLARE @RESULT INT EXEC @RESULT = ThrowError SELECT @RESULT And if I run this I get just the divide by 0 and return -1 Call from the C# code I get an extra error message Divide by zero error encountered. Transaction count after EXECUTE indicates that a COMMIT or ROLLBACK TRANSACTION tatement is missing. Previous count = 1, current count = 0. If I give the sql transaction a name then Cannot roll back SqlTransaction. No transaction or savepoint of that name was found. Transaction count after EXECUTE indicates that a COMMIT or ROLLBACK TRANSACTION statement is missing. Previous count = 1, current count = 2. some times it seems the count goes up, until the app completely exits The c# is just using (TransactionScope scope = new TransactionScope()) { ... Execute Sql scope.Commit() }

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  • MS Access (Jet) transactions, workspaces & scope

    - by Eric G
    I am having trouble with committing a transaction (using Access 2003 DAO). It's acting as if I never had called BeginTrans -- I get error 3034 on CommitTrans, "You tried to commit or rollback a transaction without first beginning a transaction"; and the changes are written to the database (presumably because they were never wrapped in a transaction). However, BeginTrans is run, if you step through it. I am running it within the Access environment using the DBEngine(0) workspace. The tables I'm updating are all opened via a Jet database connection (to the same database) and updated using DAO.Recordset.update. The connection is opened before starting BeforeTrans. I'm not doing anything weird in the middle of the transaction like closing/opening connections or multiple workspaces etc. There is one nested transaction level (basically it's wrapping multiple transacted updates in an outer transaction, so if any fail they all fail). The inner transactions run without errors, it's the outer transaction that doesn't work. Here are a few things I've looked into and ruled out: The transaction is spread across several methods and BeginTrans and CommitTrans (and Rollback) are all in different places. But when I tried a simple test of running a transaction this way, it doesn't seem like this should matter. I thought maybe the database connection gets closed when it goes out of local scope, even though I have another 'global' reference to it (I'm never sure what DAO does with dbase connections to be honest). But this seems not to be the case -- right before the commit, the connection and its recordsets are alive (I can check their properties, EOF = False, etc.) My CommitTrans and Rollback are done within event callbacks. (Very basically, a parser program is throwing an 'onLoad' or 'onLoadFail' event at the end of parsing, which I am handling by either committing or rolling back the inserts I made during processing.) However, again, trying a simple test, it doesn't seem like this should matter. Any ideas why this isn't working for me? Thanks.

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  • Should I use IDisposable for purely managed resources?

    - by John Gietzen
    Here is the scenario: I have an object called a Transaction that needs to make sure that only one entity has permission to edit it at any given time. In order to facilitate a long-lived lock, I have the class generating a token object that can be used to make the edits. You would use it like this: var transaction = new Transaction(); using (var tlock = transaction.Lock()) { transaction.Update(data, tlock); } Now, I want the TransactionLock class to implement IDisposable so that its usage can be clear. But, I don't have any unmanaged resources to dispose. however, the TransctionLock object itself is a sort of "unmanaged resource" in the sense that the CLR doesn't know how to properly finalize it. All of this would be fine and dandy, I would just use IDisposable and be done with it. However, my issue comes when I try to do this in the finalizer: ~TransactionLock() { this.Dispose(false); } I want the finalizer to release the transaction from the lock, if possible. How, in the finalizer, do I detect if the parent transaction (this.transaction) has already been finalized? Is there a better pattern I should be using? The Transaction class looks something like this: public sealed class Transaction { private readonly object lockMutex = new object(); private TransactionLock currentLock; public TransactionLock Lock() { lock (this.lockMutex) { if (this.currentLock != null) throw new InvalidOperationException(/* ... */); this.currentLock = new TransactionLock(this); return this.currentLock; } } public void Update(object data, TransactionLock tlock) { lock (this.lockMutex) { this.ValidateLock(tlock); // ... } } internal void ValidateLock(TransactionLock tlock) { if (this.currentLock == null) throw new InvalidOperationException(/* ... */); if (this.currentLock != tlock) throw new InvalidOperationException(/* ... */); } internal void Unlock(TransactionLock tlock) { lock (this.lockMutex) { this.ValidateLock(tlock); this.currentLock = null; } } }

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  • openDatabase Hello World

    - by cf_PhillipSenn
    I'm trying to learn about openDatabase, and I think this I'm getting it to INSERT INTO TABLE1, but I can't verify that the SELECT * FROM TABLE1 is working. <html> <head> <script src="http://www.google.com/jsapi"></script> <script type="text/javascript"> google.load("jquery", "1"); </script> <script type="text/javascript"> var db; $(function(){ db = openDatabase('HelloWorld'); db.transaction( function(transaction) { transaction.executeSql( 'CREATE TABLE IF NOT EXISTS Table1 ' + ' (TableID INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, ' + ' Field1 TEXT NOT NULL );' ); } ); db.transaction( function(transaction) { transaction.executeSql( 'SELECT * FROM Table1;',function (transaction, result) { for (var i=0; i < result.rows.length; i++) { alert('1'); $('body').append(result.rows.item(i)); } }, errorHandler ); } ); $('form').submit(function() { var xxx = $('#xxx').val(); db.transaction( function(transaction) { transaction.executeSql( 'INSERT INTO Table1 (Field1) VALUES (?);', [xxx], function(){ alert('Saved!'); }, errorHandler ); } ); return false; }); }); function errorHandler(transaction, error) { alert('Oops. Error was '+error.message+' (Code '+error.code+')'); transaction.executeSql('INSERT INTO errors (code, message) VALUES (?, ?);', [error.code, error.message]); return false; } </script> </head> <body> <form method="post"> <input name="xxx" id="xxx" /> <p> <input type="submit" name="OK" /> </p> <a href="http://www.google.com">Cancel</a> </form> </body> </html>

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  • OS Isolation: Virtualization or Dual-Boot Duplication, a General How To?

    - by Mr_CryptoPrime
    I want to isolate my windows 7 operating system and I have looked into virtualization. This should work with Linux, however, I do want to still have a way to run windows 7 securely, but without significant performance loss, thus eliminating virtualization for that. I know that you can dual boot because I currently do so with my XP/Linux system. Is there a way that I can duplicate my windows 7 system so I can select one at bootup? This way I can ensure that each OS is isolated and not worry about performance loss. However, I am having a lot of trouble finding a solid method for OS duplication?! Is this even possible or must I buy two versions of win7 and somehow install them separately? Any information regarding this would be helpful, thanks! Essentially I want, Two instances of win7 (not necessarily simultaneously running) Each are isolated from one another so that a security breach in one doesn't affect the other. There is no performance loss in either from doing so

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  • Using transactions with LINQ-to-SQL

    - by Jalpesh P. Vadgama
    Today one of my colleague asked that how we can use transactions with the LINQ-to-SQL Classes when we use more then one entities updated at same time. It was a good question. Here is my answer for that.For ASP.NET 2.0  or higher version have a new class called TransactionScope which can be used to manage transaction with the LINQ. Let’s take a simple scenario we are having a shopping cart application in which we are storing details or particular order placed into the database using LINQ-to-SQL. There are two tables Order and OrderDetails which will have all the information related to order. Order will store particular information about orders while OrderDetails table will have product and quantity of product for particular order.We need to insert data in both tables as same time and if any errors comes then it should rollback the transaction. To use TransactionScope in above scenario first we have add a reference to System.Transactions like below. After adding the transaction we need to drag and drop the Order and Order Details tables into Linq-To-SQL Classes it will create entities for that. Below is the code for transaction scope to use mange transaction with Linq Context. MyContextDataContext objContext = new MyContextDataContext(); using (System.Transactions.TransactionScope tScope = new System.Transactions.TransactionScope(TransactionScopeOption.Required)) { objContext.Order.InsertOnSubmit(Order); objContext.OrderDetails.InsertOnSumbit(OrderDetails); objContext.SubmitChanges(); tScope.Complete(); } Here it will commit transaction only if using blocks will run successfully. Hope this will help you. Technorati Tags: Linq,Transaction,System.Transactions,ASP.NET

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  • ASP.NET, C#: timeout when trying to Transaction.Commit() to database; potential deadlock?

    - by user1843921
    I have a web page that has coding structured somewhat as follows: SqlConnection conX =new SqlConnection(blablabla); conX.Open(); SqlTransaction tran=conX.BeginTransaction(); try{ SqlCommand cmdInsert =new SqlCommand("INSERT INTO Table1(ColX,ColY) VALUES @x,@y",conX); cmdInsert.Transaction=tran; cmdInsert.ExecuteNonQuery(); SqlCommand cmdSelect=new SqlCOmmand("SELECT * FROM Table1",conX); cmdSelect.Transaction=tran; SqlDataReader dtr=cmdSelect.ExecuteReader(); //read stuff from dtr dtr.Close(); cmdInsert=new SqlCommand("UPDATE Table2 set ColA=@a",conX); cmdInsert.Transaction=tran; cmdInsert.ExecuteNonQuery(); //display MiscMessage tran.Commit(); //display SuccessMessage } catch(Exception x) { tran.Rollback(); //display x.Message } finally { conX.Close(); } So, everything seems to work until MiscMessage. Then, after a while (maybe 15-ish seconds?) x.Message pops up, saying that: "Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding." So something wrong with my trans.Commit()? The database is not updated so I assume the trans.Rollback works... I have read that deadlocks can cause timeouts...is this problem cause by my SELECT statement selecting from Table1, which is being used by the first INSERT statement? If so, what should I do? If that ain't the problem, what is?

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  • Ways to update a dependent table in the same MySQL transaction?

    - by codie
    I need to update two tables inside a single transaction. The individual queries look something like this: 1. INSERT INTO t1 (col1, col2) VALUES (val1, val2) ON DUPLICATE KEY UPDATE col2 = val2; If the above query causes an insert then I need to run the following statement on the second table: 2. INSERT INTO t2 (col1, col2) VALUES (val1, val2) ON DUPLICATE KEY UPDATE col2 = col2 + val2; otherwise, 3. UPDATE t2 SET col2 = col2 - old_val2 + val2 WHERE col1 = val1; -- old_val2 is the value of t1.col2 before it was updated Right now I run a SELECT on t1 first, to determine whether statement 1 will cause an insert or update on t1. Then I run statement 1 and either of 2 and 3 inside a transaction. What are the ways in which I can do all of these inside one transaction itself? The approach I was thinking of is the following: UPDATE t2, t1 set t2.col2 = t2.col2 - t1.col2 WHERE t1.col1 = t2.col2 and t1.col1 = val1; INSERT INTO t1 (col1, col2) VALUES (val1, val2) ON DUPLICATE KEY UPDATE col2 = val2; INSERT INTO t2, t1 (t2.col1, t2.col2) VALUES (t1.col1, t1.col2) ON DUPLICATE KEY UPDATE t2.col2 = t2.col2 + t1.col2 WHERE t1.col1 = t2.col2 and t1.col1 = val1; Unfortunately, there's no multi-table INSERT... ON DUPLICATE KEY UPDATE in MySQL 5.0. What else could I do?

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  • Can a Snapshot transaction fail and only partially commit in a TransactionScope?

    - by Travis Brooks
    Greetings I stumbled onto a problem today that seems sort of impossible to me, but its happening...I'm calling some database code in c# that looks something like this: using(var tran = MyDataLayer.Transaction()) { MyDataLayer.ExecSproc(new SprocTheFirst(arg1, arg2)); MyDataLayer.CallSomethingThatEventuallyDoesLinqToSql(arg1, argEtc); tran.Commit(); } I've simplified this a bit for posting, but whats going on is MyDataLayer.Transaction() makes a TransactionScope with the IsolationLevel set to Snapshot and TransactionScopeOption set to Required. This code gets called hundreds of times a day, and almost always works perfectly. However after reviewing some data I discovered there are a handful of records created by "SprocTheFirst" but no corresponding data from "CallSomethingThatEventuallyDoesLinqToSql". The only way that records should exist in the tables I'm looking at is from SprocTheFirst, and its only ever called in this one function, so if its called and succeeded then I would expect CallSomethingThatEventuallyDoesLinqToSql would get called and succeed because its all in the same TransactionScope. Its theoretically possible that some other dev mucked around in the DB, but I don't think they have. We also log all exceptions, and I can find nothing unusual happening around the time that the records from SprocTheFirst were created. So, is it possible that a transaction, or more properly a declarative TransactionScope, with Snapshot isolation level can fail somehow and only partially commit?

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  • How should we deal with multiple transaction-report requests?

    - by Mithir
    We are developing a system for the retail market which one of it's features will enable clients(actually consumer clubs) to go through all transactions made by end-clients. One of the ways to get this information will be via an API. The idea is that there will be requests for reports with a start date and an end date, and a response will have all the transactions between those dates. We are worry that some reports may be very large, and that some clients will repeatedly request for reports, in this case the DB and CPU will be very overloaded. The same server that will service those requests, also takes care the the actual retail transactions (received by proprietary devices) and a Web application. We are not sure about how to limit the report requests from the API so that it won't affect the system too much. So, how should we deal with this scenario? any thoughts? EDIT: just to make clear: When I mentioned proprietary devices I meant "On-Location" devices which are used during sales with end-clients, this means that these requests shouldn't get delayed, and this is the main concern.

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  • Can Mailchimp APIs be used to send templated transaction email triggered by actions on my website?

    - by HenryW
    I am currently playing around with Mailchimp's APIs, but the documentation to me is not very clear. Here is what I actually want: Have the templates I created on Mailchimp, be visible on my own server. Assign each template I made to a specific action (logged in,subscribed, created order, or new password). This is functionality that I already tested with Mandrill, but the template exists on mandrill's account. If option 1 is not possible, can I still make my own template in my own environment, and send that template out over Mailchimp or Mandrill? Should I use Mailchimps services for this or send the email directly from my own server? Curent used function: function tep_mandrill_mail($to_name, $to_email_address, $email_subject, $email_text, $from_email_name, $from_email_address) { if (SEND_EMAILS != 'true') return false; $uri = 'https://mandrillapp.com/api/1.0/messages/send-template.json'; $postString = '{ "key": "xxxxxxxxxxx", "template_name": "sometemplatename", "template_content": [ { "name": "header", "content": "*|HEADERSTUFF|*" }, { "name": "main", "content": "*|CONTENTSTUFF|*" }, { "name": "footer", "content": "*|FOOTERSTUFF|*" } ], "message": { "subject": "'.$email_subject.'", "from_email": "'.$from_email_adress.'", "from_name": "'.$from_email_name.'", "to": [ { "email": "'.$to_email_address.'", "name": "'.$to_name.'" } ], "important": false, "track_opens": true, "merge": true, "merge_vars": [ { "rcpt": "'.$to_email_address.'", "vars": [ { "name": "HEADERSTUFF", "content": "'.$email_subject.'" }, { "name": "CONTENTSTUFF", "content": "'.$email_text.'" }, { "name": "FOOTERSTUFF", "content": "paulvale-foot" } ] } ], "tags": [ "password_forgotten" ] }, "async": false, "ip_pool": "Main Pool" }'; $ch = curl_init(); curl_setopt($ch, CURLOPT_URL, $uri); curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true ); curl_setopt($ch, CURLOPT_RETURNTRANSFER, true ); curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false); curl_setopt($ch, CURLOPT_POST, true); curl_setopt($ch, CURLOPT_POSTFIELDS, $postString); curl_exec($ch); }

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  • why are transaction monitors on decline? or are they?

    - by mrkafk
    http://www.itjobswatch.co.uk/jobs/uk/cics.do http://www.itjobswatch.co.uk/jobs/uk/tuxedo.do Look at the demand for programmers (% of job ads that the keyword appears), first graph under the table. It seems like demand for CICS, Tuxedo has fallen from 2.5%/1% respectively to almost zero. To me, it seems bizarre: now we have more networked and internet enabled machines than ever before. And most of them are talking to some kind of database. So it would seem that use of products whose developers spent last 20-30 years working on distributing and coordinating and optimizing transactions should be on the rise. And it appears they're not. I can see a few causes but can't tell whether they are true: we forgot that concurrency and distribution are really hard, and redoing it all by ourselves, in Java, badly. Erlang killed them all. Projects nowadays have changed character, like most business software has already been built and we're all doing internet services, using stuff like Node.js, Erlang, Haskell. (I've used RabbitMQ which is written in Erlang, "but it was small specialized side project" kind of thing). BigData is the emphasis now and BigData doesn't need transactions very much (?). None of those explanations seem particularly convincing to me, which is why I'm looking for better one. Anyone?

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  • Stairway to Transaction Log Management in SQL Server, Level 6: Managing the Log in BULK_LOGGED Recovery Model

    A DBA may consider switching a database to the BULK_LOGGED recovery model in the short term during, for example, bulk load operations. When a database is operating in the BULK_LOGGED model these, and a few other operations such as index rebuilds, can be minimally logged and will therefore use much less space in the log NEW! Never waste another weekend deployingDeploy SQL Server changes and ASP .NET applications fast, frequently, and without fuss, using Deployment Manager, the new tool from Red Gate. Try it now.

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  • How do I resolve an "Invalid Transaction" error saving a zone config in Brocade Web Tools?

    - by Frank Szczerba
    When trying to save zoning changes in the Zone Administration tool in Brocade Web Tools, I get the status "Failed to commit changes to fabric" and the messages window shows: --- start of commit (Enable Config) at: Fri Jul 23 2010 19:43:40 GMT+00:00 Invalid Transaction --- end of commit at: Fri Jul 23 2010 19:43:47 GMT+00:00 I've tried refreshing the config and just re-saving what is already on the switch, but can't get this message to go away.

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