Does an ADO.NET transaction need to be assigned to the command object when using Connection.CreateCommand()?

Question

I need to use transactions with a ADO.NET provider.

Below is a simple example of a connection, transaction and command being created. When I create a command using connection.CreateCommand() do I need to assign the transaction to the command? Or, is the transaction set because I'm using connection.CreateCommand() vs newing up a command object?

var connection = Database.GetConnection();
connection.Open();

var transaction = connection.BeginTransaction();

var command = connection.CreateCommand();
command.Transaction = transaction; // Is this line needed when using connection.CreateCommand()?

*Update*

When I test the reference of both objects, they are the same. I'd assume that means connection.CreateCommand() is returning a command with the transaction assigned. Or maybe that is not a valid test.

using (var connection = Database.GetConnection())
{
    connection.Open();

    var transaction = connection.BeginTransaction();

    var command = connection.CreateCommand();

    if (object.ReferenceEquals(transaction, command.Transaction))
        Debug.WriteLine("EQUAL");
}

Answer 1

You have to explicitly set the transaction for each SqlCommand instance. Here is the source code of System.Data.SqlClient.SqlConnection.cs (Line: 782) of CreateCommand:

new public SqlCommand CreateCommand() {
    return new SqlCommand(null, this);
}

As you see; It pass null for CommandText and this (itself) for SqlConnection arguments.

Answer 2

Yes, the transaction and command need to be associated with one another.

Some redacted sample code:

// Connect to the database.
SqlConnection connection = new SqlConnection(Database.ConnectionString);
connection.Open();

// Start a transaction.
SqlCommand command = new SqlCommand();
command.Connection = connection;
command.Transaction = connection.BeginTransaction(System.Data.IsolationLevel.Serializable, "ryan");

// Delete any previously associated targets.
command.CommandType = System.Data.CommandType.StoredProcedure;
command.CommandText = "FirstSP";
command.Parameters.AddWithValue("@Id", this.Id);
command.ExecuteNonQuery();

// Add the specified targets to the product.
command.CommandText = "SecondSP";
command.Parameters.Add("@Id", SqlDbType.Int);
foreach (int Id in Ids)
{
    command.Parameters["@Id"].Value = Id;
    command.ExecuteNonQuery();
}

// Commit the transaction.
command.Transaction.Commit();

// Houseclean.
connection.Close();

Answer 3

If you use TransactionScope you do not need to attach anything to the command object.

Just take a look at the example from the documentation of TransactionScope.