Question

I had previously asked about
Converting using SqlConnection to Func delegate

How can I use the following delegate to make multiple calls using the same transaction?
To complicate matters, one of the calls I wish to return a value.

I have the following Delegate function definition

protected TResult UsingSqlTransaction<TResult>(Func<SqlTransaction, TResult> myFunction)
{
    using (SqlConnection sqlConn = new SqlConnection(ConnectionString))
    {
        sqlConn.Open();
        using (SqlTransaction sqlTrans = sqlConn.BeginTransaction())
        {
            var result = myFunction(sqlTrans);
            sqlTrans.Commit();

            return result;
        }

    }
}

Current usage

public Guid? InsertUpdate(News entity)
{
    return UsingSqlTransaction(sqlTrans => data.InsertUpdate(sqlTrans, entity));
}

Solution – See the accepted answer

public Guid? InsertUpdate(News entity)
{
    return UsingSqlTransaction(sqlTrans =>
    {
        var token = data.InsertUpdate(sqlTrans, entity);
        data.DoSomethingElse(sqlTrans, entity);
        return token;
    });
}

//-- The above UsingSqlTransaction remains unchanged

Answer 1

You can use a ‘block’ lambda. Instead of:

public Guid? InsertUpdate(News entity)
{
    return UsingSqlTransaction(sqlTrans => data.InsertUpdate(sqlTrans, entity));
}

You can use (note curly braces and semicolons):

public List<Guid?> InsertUpdate(News entity)
{
    return UsingSqlTransaction(sqlTrans =>
    {
        var result = new List<Guid?>();
        result.Add(data.InsertUpdate(sqlTrans, entity));
        result.Add(data.DoSomethingElse(sqlTrans, entity));
        return result;
    });
}

Re: your update. I’d write that like this (note that you can store token and return it at the end of your lambda, just like a normal method):

public Guid? InsertUpdate(News entity)
{
    return UsingSqlTransaction(sqlTrans =>
    {
        var token = data.InsertUpdate(sqlTrans, entity);
        data.DoSomethingElse(sqlTrans, entity);
        return token;
    });
}