在事务中调用多个SQL Server存储过程

Question

为了在我当前的项目中使用,我创建了一个允许我调用SQL Server异步的类.

我的代码看起来像这样:

internal class CommandAndCallback<TCallback, TError>
{
    public SqlCommand Sql { get; set; }
    public TCallback Callback { get; set; }
    public TError Error { get; set; }
}

class MyCodes:SingletonBase<MyCodes>
{
    private static string _connString = @"Data Source=MyDB;Initial Catalog=ED;Integrated Security=True;Asynchronous Processing=true;Connection Timeout=0;Application Name=TEST";

    private MyCodes() { }

    public void SetSystem(bool production)
    {
        _connString =
            string.Format(@"Data Source=MyDB;Initial Catalog={0};Integrated Security=True;Asynchronous Processing=true;Connection Timeout=0;Application Name=TEST", production ? "ED" : "TEST_ED");
    }

    public void Add(string newCode, Action<int> callback, Action<string> error)
    {
        var conn = new SqlConnection(_connString);
        SqlCommand cmd = conn.CreateCommand();
        cmd.CommandTimeout = 0;
        cmd.CommandType = CommandType.StoredProcedure;
        cmd.CommandText = @"ADD_CODE";
        cmd.Parameters.Add("@NEW", SqlDbType.NVarChar).Value = newCode;
        cmd.Parameters.Add("@NewId", SqlDbType.Int).Direction = ParameterDirection.Output;

        try
        {
            cmd.Connection.Open();
        }
        catch (Exception ex)
        {
            error(ex.ToString());
            return;
        }

        var ar = new CommandAndCallback<Action<int>, Action<string>> { Callback = callback, Error = error, Sql = cmd };
        cmd.BeginExecuteReader(Add_Handler, ar, CommandBehavior.CloseConnection);
    }

    private static void Add_Handler(IAsyncResult result)
    {
        var ar = (CommandAndCallback<Action<int>, Action<string>>)result.AsyncState;
        if (result.IsCompleted)
        {
            try
            {
                ar.Sql.EndExecuteReader(result);
                ar.Callback(Convert.ToInt32(ar.Sql.Parameters["@NewId"].Value));
            }
            catch (Exception ex)
            {
                ar.Error(ex.Message);
            }
        }
        else
        {
            ar.Error("Error executing SQL");
        }
    }

public void Update(int codeId, string newCode, Action callback, Action<string> error)
    {
        var conn = new SqlConnection(_connString);
        SqlCommand cmd = conn.CreateCommand();
        cmd.CommandTimeout = 0;
        cmd.CommandType = CommandType.StoredProcedure;
        cmd.CommandText = @"UPDATE_CODE";
        cmd.Parameters.Add("@CODE_ID", SqlDbType.Int).Value = codeId;
        cmd.Parameters.Add("@NEW", SqlDbType.NVarChar).Value = newCode;

        try
        {
            cmd.Connection.Open();
        }
        catch (Exception ex)
        {
            error(ex.ToString());
            return;
        }

        var ar = new CommandAndCallback<Action, Action<string>> { Callback = callback, Error = error, Sql = cmd };
        cmd.BeginExecuteReader(Update_Handler, ar, CommandBehavior.CloseConnection);
    }

    private static void Update_Handler(IAsyncResult result)
    {
        var ar = (CommandAndCallback<Action, Action<string>>)result.AsyncState;
        if (result.IsCompleted)
        {
            try
            {
                ar.Sql.EndExecuteReader(result);
                ar.Callback();
            }
            catch (Exception ex)
            {
                ar.Error(ex.Message);
            }
        }
        else
        {
            ar.Error("Error executing SQL");
        }
    }

}

这可能看起来像是太多的代码,但它让我这样称呼它:

private void Add_Click(object sender, EventArgs e)
{
   MyCodes.Instance.Add("Test",Success,Error)
}

private void Success(int newId)
{
   MessageBox.Show(newId.ToString(), "Success", MessageBoxButtons.OK, MessageBoxIcon.Information);
}

private void Error(string error)
{
   MessageBox.Show(error, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
}

上面的代码对我来说很好,我能够做每个调用异步.

我现在遇到的问题是作为交易进行多次调用 - 我想更新2个代码并添加一个新代码.

通常我会调用update,然后在成功处理程序中调用第二次更新,并在处理程序中进行第二次更新,我会调用add将返回新的id.

就像是:

-UPDATE CODE
 |-UPDATE CODE
   |-ADD CODE (only this one return something)

但是我想把所有这些都称为事务,所以如果添加代码会破坏更新会回滚.

题:

是否可以将多个异步查询作为事务调用？

我可以将上述方法称为事务,还是必须创建单独的方法来将我的过程称为一个？(我想避免这个,因为它只是将相同的代码从一个方法复制到另一个方法)

我想补充一点,我使用.NET 3.5所以等待和其他不错的功能不是一个选项.

Answer 1

  string cnnString =WebConfigurationManager.ConnectionStrings["MyString"].ConnectionString;
    SqlConnection cnn = new SqlConnection(cnnString);
    SqlTransaction transaction;

    cnn.Open();
    transaction = cnn.BeginTransaction();

    try
    {

        // Command Objects for the transaction
        SqlCommand cmd1 = new SqlCommand("sproc1", cnn);
        SqlCommand cmd2 = new SqlCommand("sproc2", cnn);

        cmd1.CommandType = CommandType.StoredProcedure;
        cmd2.CommandType = CommandType.StoredProcedure;

        cmd1.Parameters.Add(new SqlParameter("@Param1", SqlDbType.NVarChar, 50));
        cmd1.Parameters["@Param1"].Value = paramValue1;

        cmd1.Parameters.Add(new SqlParameter("@Param2", SqlDbType.NVarChar, 50));
        cmd1.Parameters["@Param2"].Value = paramValue2;

        cmd2.Parameters.Add(new SqlParameter("@Param3", SqlDbType.NVarChar, 50));
        cmd2.Parameters["@Param3"].Value = paramValue3;

        cmd2.Parameters.Add(new SqlParameter("@Param4", SqlDbType.NVarChar, 50));
        cmd2.Parameters["@Param4"].Value = paramValue4;

        cmd1.ExecuteNonQuery();
        cmd2.ExecuteNonQuery();

        transaction.Commit();
    }

    catch (SqlException sqlEx)
    {
        transaction.Rollback();
    }

    finally
    {
        cnn.Close();
        cnn.Dispose();
    }

Answer 2

对的,这是可能的.只需SqlConnection.BeginTransaction在第一次调用之前调用,就可以将返回的SqlTransaction对象分配给SqlCommand.Transaction链中的每个对象并SqlTransaction.Commit()在最后调用.