为什么锁的信息在5-6秒后出现得这么晚？

Question

我有一个简单的应用程序，有两个按钮。第一个按钮create transaction，在提交之前保持30秒。

第二个按钮execute方法，我试图更新相同的记录。

我的观点是获取有关锁定记录的信息，但在5-6秒后抛出异常。

在运行过程中，有关锁的信息会立即出现。

如何在C#中实现类似的效率？

    private void button1_Click(object sender, RoutedEventArgs e)
    {
        Task.Run(  () =>
        {
            using (OdbcConnection con = new OdbcConnection("DSN=myDSN;UID=root;PWD=qweasd"))
            {
                OdbcCommand command = new OdbcCommand();
                OdbcTransaction transaction = null;

                command.Connection = con;

                try
                {
                    con.Open();

                    while (con.State != ConnectionState.Open)
                    {
                        Thread.Sleep(10);
                    }

                    transaction = con.BeginTransaction();

                    command.Connection = con;
                    command.Transaction = transaction;

                    command.CommandText = " UPDATE pub.ad_mstr SET ad_line1 = 'button3' where ad_mstr.ad_addr = 'abcdefgh'  ";

                    command.CommandTimeout = 1;
                    command.ExecuteNonQuery();

                    for (int i = 0; i < 30; i++)
                    {
                        Thread.Sleep(1000);
                    }


                    transaction.Commit();

                }
                catch (Exception exc)
                {
                    try
                    {
                        transaction.Rollback();
                    }
                    catch
                    {

                    }
                }

            }
            //_startedTransaction1 = true;
        }); /* Task.Run ( () => */
    }

    private void button2_Click(object sender, RoutedEventArgs e)
    {
        if (!_startedTransaction1)
        {
            Task.Run(() =>
            {
                using (OdbcConnection con = new OdbcConnection("DSN=myDSN;UID=root;PWD=qweasd"))
                {
                    OdbcCommand command = new OdbcCommand();
                    OdbcTransaction transaction = null;

                    command.Connection = con;

                    try
                    {
                        con.Open();
                        while (con.State != ConnectionState.Open)
                        {
                            Thread.Sleep(10);
                        }

                        transaction = con.BeginTransaction();

                        command.Connection = con;
                        command.Transaction = transaction;

                        command.CommandText = " UPDATE pub.ad_mstr SET ad_name = 'button1' where ad_mstr.ad_addr = 'abcdefgh'  ";

                        command.ExecuteNonQuery();

                        transaction.Commit();

                    }
                    catch (Exception exc)
                    {
                        try
                        {
                            transaction.Rollback();
                        }
                        catch
                        {

                        }
                    }

                    //_startedTransaction1 = true;
                }
            });
        }
        else
        {
            //_startedTransaction1 = false;
        }

    }

我想补充的是，我的'myDSN‘是提交的隔离级别。5-6秒后出现的异常情况为：

"System.Collections.ListDictionaryInternal pgoe1023.dll ERROR HY000ODBC Progress Wire Protocol driverFailure在表PUB.ad_mstr的记录上获取记录锁定。“

Answer 1

看起来您应该在DB服务器上设置-SQLLockWaitTimeout参数：

http://knowledgebase.progress.com/articles/Article/What-is-the-SQLLockWaitTimeout-Parameter