如何在实体框架中回滚事务

发布于 2024-07-25 17:50:46 字数 496 浏览 2 评论 0原文

string[] usersToAdd = new string[] { "asd", "asdert", "gasdff6" };
using (Entities context = new Entities())
{
    foreach (string user in usersToAdd)
    {
        context.AddToUsers(new User { Name = user });
    }
    try
    {
        context.SaveChanges(); //Exception thrown: user 'gasdff6' already exist.
    }
    catch (Exception e)
    {
        //Roll back all changes including the two previous users.
    }

或者这可能是自动完成的，这意味着如果发生错误，所有更改的提交更改都会被取消。是吗？

原文

string[] usersToAdd = new string[] { "asd", "asdert", "gasdff6" };
using (Entities context = new Entities())
{
    foreach (string user in usersToAdd)
    {
        context.AddToUsers(new User { Name = user });
    }
    try
    {
        context.SaveChanges(); //Exception thrown: user 'gasdff6' already exist.
    }
    catch (Exception e)
    {
        //Roll back all changes including the two previous users.
    }

Or maybe this is done automatically, meaning that if error occurs, committing changes are canceled for all the changes.
is it?

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木格 2024-08-01 17:50:46

好的，

我创建了一个示例应用程序，例如我在数据库中检查的问题和后记中的示例，但没有添加用户。

结论：ObjectContext.SaveChange 它自动成为一个事务。

注意：我相信如果执行存储过程等，将需要事务。

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爱*していゐ 2024-08-01 17:50:46

我相信（但我不是 EF 的长期专家）在调用 context.SaveChanges 之前，事务不会启动。我预计该调用的异常会自动回滚它启动的任何事务。
替代方案（如果您想控制交易）[来自 J.Lerman 的“编程实体框架” 奥莱利，第 17 页。 618章

using (var transaction = new System.Transactions.TransactionScope())
{
  try
  {
    context.SaveChanges();
    transaction.Complete();
    context.AcceptAllChanges();
  }
  catch(OptimisticConcurrencyException e)
  {
    //Handle the exception
    context.SaveChanges();
  }
}

第

bool saved = false;
using (var transaction = new System.Transactions.TransactionScope())
{
  try
  {
    context.SaveChanges();
    saved = true;
  }
  catch(OptimisticConcurrencyException e)
  {
    //Handle the exception
    context.SaveChanges();
  }
  finally
  {
    if(saved)
    {
      transaction.Complete();
      context.AcceptAllChanges();
    }
  }

}

I believe (but I am no long time expert in EF) that until the call to context.SaveChanges goes through, the transaction is not started. I'd expect an Exception from that call would automatically rollback any transaction it started.
Alternatives (in case you want to be in control of the transaction) [from J.Lerman's "Programming Entity Framework" O'Reilly, pg. 618]

using (var transaction = new System.Transactions.TransactionScope())
{
  try
  {
    context.SaveChanges();
    transaction.Complete();
    context.AcceptAllChanges();
  }
  catch(OptimisticConcurrencyException e)
  {
    //Handle the exception
    context.SaveChanges();
  }
}

bool saved = false;
using (var transaction = new System.Transactions.TransactionScope())
{
  try
  {
    context.SaveChanges();
    saved = true;
  }
  catch(OptimisticConcurrencyException e)
  {
    //Handle the exception
    context.SaveChanges();
  }
  finally
  {
    if(saved)
    {
      transaction.Complete();
      context.AcceptAllChanges();
    }
  }

}

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