Entity Framework: How to put multiple stored procedures in a transaction?

Question

I did a lot search already but couldn't find a straight anwser.

I have two stored procedures and they both were function imported to the DBContext object

1. InsertA()
2. InsertB()

I want to put them in a transaction. (i.e. if InsertB() failed, rolled back InsertA())

How do I do that? Can I just declare a TransactionScope object and wrap around the two stored procedures?

Thanks

Solution 1

You need to enlist your operations in a transaction scope, as follows:

using(TransactionScope tranScope = new TransactionScope()) 
{
  InsertA();
  InsertB();

  tranScope.Complete();
}

On error, the transaction scope will automatically be rolled back. Of course, you still need to handle exceptions and do whatever your exception handling design dictates (log, etc). But unless you manually call Complete(), the transaction is rolled back when the using scope ends.

The transaction scope will not be promoted to a distributed transaction unless you open other database connections in the same transaction scope (see here).

This is important to know because otherwise you would need to configure MSDTC on all your servers involved in this operation (web, middle tier eventually, sql server). So, as long as the transaction isn't promoted to a distributed one, you'll be fine.

Note: In order to fine-tune your transaction options, such as timeouts and isolation levels, have a look at this TransactionScope constructor. Default isolation level is serializable.

Additional sample: here.

Solution 2

You can use the TransactionScope object or you can use the SqlConnection.BeginTransaction Method. Be careful using TransactionScope, transactions can be esculated to distributed transactions when calling stored procedures in a different database. Distributed transactions can be resource intensive.

How to use sqlConnection.BeginTransaction...(http://msdn.microsoft.com/en-us/library/86773566.aspx)

private static void ExecuteSqlTransaction(string connectionString)
{
    using (SqlConnection connection = new SqlConnection(connectionString))
    {
        connection.Open();

        SqlCommand command = connection.CreateCommand();
        SqlTransaction transaction;

        // Start a local transaction.
        transaction = connection.BeginTransaction("SampleTransaction");

        // Must assign both transaction object and connection
        // to Command object for a pending local transaction
        command.Connection = connection;
        command.Transaction = transaction;

        try
        {
            command.CommandText =
                "Insert into Region (RegionID, RegionDescription) VALUES (100, 'Description')";
            command.ExecuteNonQuery();
            command.CommandText =
                "Insert into Region (RegionID, RegionDescription) VALUES (101, 'Description')";
            command.ExecuteNonQuery();

            // Attempt to commit the transaction.
            transaction.Commit();
            Console.WriteLine("Both records are written to database.");
        }
        catch (Exception ex)
        {
            Console.WriteLine("Commit Exception Type: {0}", ex.GetType());
            Console.WriteLine("  Message: {0}", ex.Message);

            // Attempt to roll back the transaction.
            try
            {
                transaction.Rollback();
            }
            catch (Exception ex2)
            {
                // This catch block will handle any errors that may have occurred
                // on the server that would cause the rollback to fail, such as
                // a closed connection.
                Console.WriteLine("Rollback Exception Type: {0}", ex2.GetType());
                Console.WriteLine("  Message: {0}", ex2.Message);
            }
        }
    }
}

How to use TransactionScope...(http://msdn.microsoft.com/en-us/library/system.transactions.transactionscope.aspx)

// This function takes arguments for 2 connection strings and commands to create a transaction 
// involving two SQL Servers. It returns a value > 0 if the transaction is committed, 0 if the 
// transaction is rolled back. To test this code, you can connect to two different databases 
// on the same server by altering the connection string, or to another 3rd party RDBMS by 
// altering the code in the connection2 code block.
static public int CreateTransactionScope(
    string connectString1, string connectString2,
    string commandText1, string commandText2)
{
    // Initialize the return value to zero and create a StringWriter to display results.
    int returnValue = 0;
    System.IO.StringWriter writer = new System.IO.StringWriter();

    try
    {
        // Create the TransactionScope to execute the commands, guaranteeing
        // that both commands can commit or roll back as a single unit of work.
        using (TransactionScope scope = new TransactionScope())
        {
            using (SqlConnection connection1 = new SqlConnection(connectString1))
            {
                // Opening the connection automatically enlists it in the 
                // TransactionScope as a lightweight transaction.
                connection1.Open();

                // Create the SqlCommand object and execute the first command.
                SqlCommand command1 = new SqlCommand(commandText1, connection1);
                returnValue = command1.ExecuteNonQuery();
                writer.WriteLine("Rows to be affected by command1: {0}", returnValue);

                // If you get here, this means that command1 succeeded. By nesting
                // the using block for connection2 inside that of connection1, you
                // conserve server and network resources as connection2 is opened
                // only when there is a chance that the transaction can commit.   
                using (SqlConnection connection2 = new SqlConnection(connectString2))
                {
                    // The transaction is escalated to a full distributed
                    // transaction when connection2 is opened.
                    connection2.Open();

                    // Execute the second command in the second database.
                    returnValue = 0;
                    SqlCommand command2 = new SqlCommand(commandText2, connection2);
                    returnValue = command2.ExecuteNonQuery();
                    writer.WriteLine("Rows to be affected by command2: {0}", returnValue);
                }
            }

            // The Complete method commits the transaction. If an exception has been thrown,
            // Complete is not  called and the transaction is rolled back.
            scope.Complete();

        }

    }
    catch (TransactionAbortedException ex)
    {
        writer.WriteLine("TransactionAbortedException Message: {0}", ex.Message);
    }
    catch (ApplicationException ex)
    {
        writer.WriteLine("ApplicationException Message: {0}", ex.Message);
    }

    // Display messages.
    Console.WriteLine(writer.ToString());

    return returnValue;
}

Comments

[Marcel N.]

But that's a whole lot of code for something that can be done with only a few lines of code, using proper transactions support.

[c830]

Thanks for the detailed answer.