Search for uncommitted data

I was doing tests regarding transactions and I saw that if I conduct a search of the registered and uncommitted data they are returned. In the entity framework this does not happen, and from what I researched behind the scenes he works with transactions.

Someone knows how I can get around this:

var conn = new SqlConnection(ConfigurationManager.
                ConnectionStrings["connNorthwind"].ConnectionString);

        conn.Open();
        var transaction = conn.BeginTransaction();

        string productName = "tEST1";


        var commad1 = conn.CreateCommand();
        commad1.Transaction = transaction;

        var commad2 = conn.CreateCommand();
        commad2.Transaction = transaction;

        var commad3 = conn.CreateCommand();
        commad3.Transaction = transaction; 


        commad1.CommandText = "INSERT products(ProductName, Discontinued)VALUES ('" + productName + "', 'true')";
        commad1.ExecuteNonQuery();

        commad2.CommandText = "INSERT products(ProductName, Discontinued)VALUES ('" + productName + "', 'true')";
        commad2.ExecuteNonQuery();

        commad3.CommandText = "SELECT * FROM products where ProductName like '%" + productName + "%'";
        var reader = commad3.ExecuteReader(System.Data.CommandBehavior.SingleResult);

        bool produtoExistente = false;
        if (reader.HasRows)
        {
            produtoExistente = true;
        }


        Assert.IsFalse(produtoExistente);