Using Multiple Data Readers

Question

I am developing a WinForm Application in C Sharp on the .net framework. The database string I am using as of now is

Answer 1

Sure:

public void SignUpControllerDay()
{
    using (var conn = new SqlConnection(ConnectionString))
    using (var cmd = conn.CreateCommand())
    {
        conn.Open();
        cmd.CommandText = "SELECT ...";
        using (var reader = cmd.ExecuteReader())
        {
            while (reader.Read())
            {
                var phone = reader["Phone_Number"].ToString();
                Bar(phone);
            }
        }
    }
}

public void Bar(string phone)
{
    using (var conn = new SqlConnection(ConnectionString))
    using (var cmd = conn.CreateCommand())
    {
        conn.Open();
        cmd.CommandText = "SELECT ..."; // use phone to prepare statement
        using (var reader = cmd.ExecuteReader())
        {
            while (reader.Read())
            {
                // Fill the grid
            }
        }
    }
}