在.net中使用TransactionScopeOption.Suppress时，为什么忽略隔离级别

I'm trying to execute an query with the isolation level read uncommitted within an existing transaction using LINQ TO SQL. If I use the option to suppress this transaction from the parent transaction, it seems I lose the ability to specify the isolation level. Using this code in LINQPad:

我正在尝试使用LINQ TO SQL在现有事务中使用未提交的隔离级别读取执行查询。如果我使用该选项从父事务中禁止此事务，似乎我失去了指定隔离级别的能力。在LINQPad中使用此代码：

void Main()
{
var db = this;
db.ExecuteQuery<string>(@"SET TRANSACTION ISOLATION LEVEL SERIALIZABLE");

using (var trans = new TransactionScope(TransactionScopeOption.Required))
{
    // updates or inserts here

    using (new TransactionScope(TransactionScopeOption.Suppress,
        new TransactionOptions { IsolationLevel = System.Transactions.IsolationLevel.ReadUncommitted }))
    {
        db.ExecuteQuery<string>(@"SELECT CASE transaction_isolation_level 
        WHEN 0 THEN 'Unspecified' 
        WHEN 1 THEN 'ReadUncomitted' 
        WHEN 2 THEN 'Readcomitted' 
        WHEN 3 THEN 'Repeatable' 
        WHEN 4 THEN 'Serializable' 
        WHEN 5 THEN 'Snapshot' END AS TRANSACTION_ISOLATION_LEVEL 
        FROM sys.dm_exec_sessions 
        where session_id = @@SPID
        ").Dump("Inside the transaction");

    }
    // updates or inserts here
}
}

I get the result of SERIALIZABLE. Is there any way to run a query inside a transaction and change the isolation level to read uncommitted?

我得到了SERIALIZABLE的结果。有没有办法在事务中运行查询并将隔离级别更改为读取未提交？

1 个解决方案

#1

What you want to use is TransactionScopeOption.RequiresNew. The Supress option causes your enclosing block to run without an ambient transaction and also without creating a new one. That's what it does.

您要使用的是TransactionScopeOption.RequiresNew。 Supress选项使您的封闭块在没有环境事务的情况下运行，也无需创建新的封闭块。这就是它的作用。

RequiresNew causes a new, root transaction scope to be created.

RequiresNew导致创建新的根事务范围。

See the summary table in this article on how different options behave.

请参阅本文中的摘要表，了解不同选项的行为方式。

#1